Proteins isolated from the outer membrane of Gram-negative bacteria.
Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.
Proteins obtained from ESCHERICHIA COLI.
A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.
Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.
The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.
Proteins found in any species of bacterium.
Bacteria which lose crystal violet stain but are stained pink when treated by Gram's method.
The space between the inner and outer membranes of a cell that is shared with the cell wall.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.
Substances elaborated by bacteria that have antigenic activity.
Lipid-containing polysaccharides which are endotoxins and important group-specific antigens. They are often derived from the cell wall of gram-negative bacteria and induce immunoglobulin secretion. The lipopolysaccharide molecule consists of three parts: LIPID A, core polysaccharide, and O-specific chains (O ANTIGENS). When derived from Escherichia coli, lipopolysaccharides serve as polyclonal B-cell mitogens commonly used in laboratory immunology. (From Dorland, 28th ed)
Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.
The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.
A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.
Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.
Cell-surface components or appendages of bacteria that facilitate adhesion (BACTERIAL ADHESION) to other cells or to inanimate surfaces. Most fimbriae (FIMBRIAE, BACTERIAL) of gram-negative bacteria function as adhesins, but in many cases it is a minor subunit protein at the tip of the fimbriae that is the actual adhesin. In gram-positive bacteria, a protein or polysaccharide surface layer serves as the specific adhesin. What is sometimes called polymeric adhesin (BIOFILMS) is distinct from protein adhesin.
Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.
The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.
Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.
A mixture of polymyxins B1 and B2, obtained from Bacillus polymyxa strains. They are basic polypeptides of about eight amino acids and have cationic detergent action on cell membranes. Polymyxin B is used for infections with gram-negative organisms, but may be neurotoxic and nephrotoxic.
The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.
The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).
Lipid A is the biologically active component of lipopolysaccharides. It shows strong endotoxic activity and exhibits immunogenic properties.
Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.
Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.
Lipid-protein complexes involved in the transportation and metabolism of lipids in the body. They are spherical particles consisting of a hydrophobic core of TRIGLYCERIDES and CHOLESTEROL ESTERS surrounded by a layer of hydrophilic free CHOLESTEROL; PHOSPHOLIPIDS; and APOLIPOPROTEINS. Lipoproteins are classified by their varying buoyant density and sizes.
Thin, hairlike appendages, 1 to 20 microns in length and often occurring in large numbers, present on the cells of gram-negative bacteria, particularly Enterobacteriaceae and Neisseria. Unlike flagella, they do not possess motility, but being protein (pilin) in nature, they possess antigenic and hemagglutinating properties. They are of medical importance because some fimbriae mediate the attachment of bacteria to cells via adhesins (ADHESINS, BACTERIAL). Bacterial fimbriae refer to common pili, to be distinguished from the preferred use of "pili", which is confined to sex pili (PILI, SEX).
The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.
Immunoglobulins produced in a response to BACTERIAL ANTIGENS.
Processes involved in the formation of TERTIARY PROTEIN STRUCTURE.
Transport proteins that carry specific substances in the blood or across cell membranes.
Extrachromosomal, usually CIRCULAR DNA molecules that are self-replicating and transferable from one organism to another. They are found in a variety of bacterial, archaeal, fungal, algal, and plant species. They are used in GENETIC ENGINEERING as CLONING VECTORS.
Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.
Those components of an organism that determine its capacity to cause disease but are not required for its viability per se. Two classes have been characterized: TOXINS, BIOLOGICAL and surface adhesion molecules that effect the ability of the microorganism to invade and colonize a host. (From Davis et al., Microbiology, 4th ed. p486)
The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.
Immunologic method used for detecting or quantifying immunoreactive substances. The substance is identified by first immobilizing it by blotting onto a membrane and then tagging it with labeled antibodies.
A serotype of Salmonella enterica that is a frequent agent of Salmonella gastroenteritis in humans. It also causes PARATYPHOID FEVER.
Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.
The sum of the weight of all the atoms in a molecule.
A species of gram-negative, aerobic BACTERIA. It is a commensal and pathogen only of humans, and can be carried asymptomatically in the NASOPHARYNX. When found in cerebrospinal fluid it is the causative agent of cerebrospinal meningitis (MENINGITIS, MENINGOCOCCAL). It is also found in venereal discharges and blood. There are at least 13 serogroups based on antigenic differences in the capsular polysaccharides; the ones causing most meningitis infections being A, B, C, Y, and W-135. Each serogroup can be further classified by serotype, serosubtype, and immunotype.
The study of crystal structure using X-RAY DIFFRACTION techniques. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)
The functional hereditary units of BACTERIA.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).
The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).
Substances that reduce the growth or reproduction of BACTERIA.
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.
Type species of CHLAMYDIA causing a variety of ocular and urogenital diseases.
The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.
Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.
Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.
A species of HAEMOPHILUS found on the mucous membranes of humans and a variety of animals. The species is further divided into biotypes I through VIII.
The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.
A species of gram-negative, aerobic bacteria primarily found in purulent venereal discharges. It is the causative agent of GONORRHEA.
Suspensions of attenuated or killed bacteria administered for the prevention or treatment of infectious bacterial disease.
Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.
The motion of phospholipid molecules within the lipid bilayer, dependent on the classes of phospholipids present, their fatty acid composition and degree of unsaturation of the acyl chains, the cholesterol concentration, and temperature.
A genus of CHLAMYDOPHILA infecting primarily birds. It contains eight known serovars, some of which infect more than one type of host, including humans.
Amino acid sequences found in transported proteins that selectively guide the distribution of the proteins to specific cellular compartments.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
A species of gram-negative, aerobic, rod-shaped bacteria commonly isolated from clinical specimens (wound, burn, and urinary tract infections). It is also found widely distributed in soil and water. P. aeruginosa is a major agent of nosocomial infection.
Proteins found in the PERIPLASM of organisms with cell walls.
Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.
The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.
Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.
Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)
Proteins involved in the transport of specific substances across the membranes of the MITOCHONDRIA.
Physicochemical property of fimbriated (FIMBRIAE, BACTERIAL) and non-fimbriated bacteria of attaching to cells, tissue, and nonbiological surfaces. It is a factor in bacterial colonization and pathogenicity.
Sites on an antigen that interact with specific antibodies.
The natural bactericidal property of BLOOD due to normally occurring antibacterial substances such as beta lysin, leukin, etc. This activity needs to be distinguished from the bactericidal activity contained in a patient's serum as a result of antimicrobial therapy, which is measured by a SERUM BACTERICIDAL TEST.
Proteins prepared by recombinant DNA technology.
Antibodies produced by a single clone of cells.
A metallic element with atomic symbol Fe, atomic number 26, and atomic weight 55.85. It is an essential constituent of HEMOGLOBINS; CYTOCHROMES; and IRON-BINDING PROTEINS. It plays a role in cellular redox reactions and in the transport of OXYGEN.
Established cell cultures that have the potential to propagate indefinitely.
Glycoproteins found on the membrane or surface of cells.
The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Gram-negative aerobic cocci of low virulence that colonize the nasopharynx and occasionally cause MENINGITIS; BACTEREMIA; EMPYEMA; PERICARDITIS; and PNEUMONIA.
A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.
The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
Identification of proteins or peptides that have been electrophoretically separated by blot transferring from the electrophoresis gel to strips of nitrocellulose paper, followed by labeling with antibody probes.
An iron-binding cyclic trimer of 2,3-dihydroxy-N-benzoyl-L-serine. It is produced by E COLI and other enteric bacteria.
Low-molecular-weight compounds produced by microorganisms that aid in the transport and sequestration of ferric iron. (The Encyclopedia of Molecular Biology, 1994)
Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.
A cyclic peptide consisting of three residues of delta-N-hydroxy-delta-N-acetylornithine. It acts as an iron transport agent in Ustilago sphaerogena.
The arrangement of two or more amino acid or base sequences from an organism or organisms in such a way as to align areas of the sequences sharing common properties. The degree of relatedness or homology between the sequences is predicted computationally or statistically based on weights assigned to the elements aligned between the sequences. This in turn can serve as a potential indicator of the genetic relatedness between the organisms.
Bacteriocins elaborated by strains of Escherichia coli and related species. They are proteins or protein-lipopolysaccharide complexes lethal to other strains of the same species.
Microscopy in which the samples are first stained immunocytochemically and then examined using an electron microscope. Immunoelectron microscopy is used extensively in diagnostic virology as part of very sensitive immunoassays.
Proteins encoded by the mitochondrial genome or proteins encoded by the nuclear genome that are imported to and resident in the MITOCHONDRIA.
The degree of pathogenicity within a group or species of microorganisms or viruses as indicated by case fatality rates and/or the ability of the organism to invade the tissues of the host. The pathogenic capacity of an organism is determined by its VIRULENCE FACTORS.
The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.
The rate dynamics in chemical or physical systems.

Membrane deinsertion of SecA underlying proton motive force-dependent stimulation of protein translocation. (1/8526)

The proton motive force (PMF) renders protein translocation across the Escherichia coli membrane highly efficient, although the underlying mechanism has not been clarified. The membrane insertion and deinsertion of SecA coupled to ATP binding and hydrolysis, respectively, are thought to drive the translocation. We report here that PMF significantly decreases the level of membrane-inserted SecA. The prlA4 mutation of SecY, which causes efficient protein translocation in the absence of PMF, was found to reduce the membrane-inserted SecA irrespective of the presence or absence of PMF. The PMF-dependent decrease in the membrane-inserted SecA caused an increase in the amount of SecA released into the extra-membrane milieu, indicating that PMF deinserts SecA from the membrane. The PMF-dependent deinsertion reduced the amount of SecA required for maximal translocation activity. Neither ATP hydrolysis nor exchange with external SecA was required for the PMF-dependent deinsertion of SecA. These results indicate that the SecA deinsertion is a limiting step of protein translocation and is accelerated by PMF, efficient protein translocation thereby being caused in the presence of PMF.  (+info)

Cloning and characterisation of a novel ompB operon from Vibrio cholerae 569B. (2/8526)

The ompB operon of Vibrio cholerae 569B has been cloned and fully sequenced. The operon encodes two proteins, OmpR and EnvZ, which share sequence identity with the OmpR and EnvZ proteins of a variety of other bacteria. Although the order of the ompR and envZ genes of V. cholerae is similar to that of the ompB operon of E. coli, S. typhimurium and X. nematophilus, the Vibrio operon exhibits a number of novel features. The structural organisation and features of the V. cholerae ompB operon are described.  (+info)

Role of DnaK in in vitro and in vivo expression of virulence factors of Vibrio cholerae. (3/8526)

The dnaK gene of Vibrio cholerae was cloned, sequenced, and used to construct a dnaK insertion mutant which was then used to examine the role of DnaK in expression of the major virulence factors of this important human pathogen. The central regulator of several virulence genes of V. cholerae is ToxR, a transmembrane DNA binding protein. The V. cholerae dnaK mutant grown in standard laboratory medium exhibited phenotypes characteristic of cells deficient in ToxR activity. Using Northern blot analysis and toxR transcriptional fusions, we demonstrated a reduction in expression of the toxR gene in the dnaK mutant strain together with a concomitant increase in expression of a htpG-like heat shock gene that is located immediately upstream and is divergently transcribed from toxR. This may be due to increased heat shock induction in the dnaK mutant. In vivo, however, although expression from heat shock promoters in the dnaK mutant was similar to that observed in vitro, expression of both toxR and htpG was comparable to that by the parental strain. In both strains, in vivo expression of toxR was significantly higher than that observed in vitro, but no reciprocal decrease in htpG expression was observed. These results suggest that the modulation of toxR expression in vivo may be different from that observed in vitro.  (+info)

Role of Bordetella pertussis virulence factors in adherence to epithelial cell lines derived from the human respiratory tract. (4/8526)

During colonization of the respiratory tract by Bordetella pertussis, virulence factors contribute to adherence of the bacterium to the respiratory tract epithelium. In the present study, we examined the roles of the virulence factors filamentous hemagglutinin (FHA), fimbriae, pertactin (Prn), and pertussis toxin (PT) in the adherence of B. pertussis to cells of the human bronchial epithelial cell line NCI-H292 and of the laryngeal epithelial cell line HEp-2. Using B. pertussis mutant strains and purified FHA, fimbriae, Prn, and PT, we demonstrated that both fimbriae and FHA are involved in the adhesion of B. pertussis to laryngeal epithelial cells, whereas only FHA is involved in the adherence to bronchial epithelial cells. For PT and Prn, no role as adhesion factor was found. However, purified PT bound to both bronchial and laryngeal cells and as such reduced the adherence of B. pertussis to these cells. These data may imply that fimbriae play a role in infection of only the laryngeal mucosa, while FHA is the major factor in colonization of the entire respiratory tract.  (+info)

Functional activities and epitope specificity of human and murine antibodies against the class 4 outer membrane protein (Rmp) of Neisseria meningitidis. (5/8526)

Antibodies against the class 4 outer membrane protein (OMP) from Neisseria meningitidis have been purified from sera from vaccinees immunized with the Norwegian meningococcal group B outer membrane vesicle vaccine. The human sera and purified antibodies reacted strongly with the class 4 OMP in immunoblots, whereas experiments with whole bacteria showed only weak reactions, indicating that the antibodies mainly reacted with parts of the class 4 molecule that were not exposed. The purified human anti-class 4 OMP antibodies and the monoclonal antibodies (MAbs) were neither bactericidal nor opsonic against live meningococci. Three new MAbs against the class 4 OMP were generated and compared with other, previously described MAbs. Three linear epitopes in different regions of the class 4 OMP were identified by the reaction of MAbs with synthetic peptides. The MAbs showed no blocking effect on bactericidal activity of MAbs against other OMPs. However, one of the eight purified human anti-class 4 OMP antibody preparations, selected from immunoblot reactions among sera from 27 vaccinees, inhibited at high concentrations the bactericidal effect of a MAb against the class 1 OMP. However, these antibodies were not vaccine induced, as they were present also before vaccination. Therefore, this study gave no evidence that vaccination with a meningococcal outer membrane vesicle vaccine containing the class 4 OMP induces blocking antibodies. Our data indicated that the structure of class 4 OMP does not correspond to standard beta-barrel structures of integral OMPs and that no substantial portion of the OmpA-like C-terminal region of this protein is located at the surface of the outer membrane.  (+info)

The levels and bactericidal capacity of antibodies directed against the UspA1 and UspA2 outer membrane proteins of Moraxella (Branhamella) catarrhalis in adults and children. (6/8526)

The UspA1 and UspA2 proteins from Moraxella catarrhalis share antigenic epitopes and are promising vaccine candidates. In this study, the levels and bactericidal activities of antibodies in sera from healthy adults and children toward UspA1 and UspA2 from the O35E strain were measured. Human sera contained antibodies to both proteins, and the levels of immunoglobulin G (IgG) antibodies were age dependent. Adult sera had significantly higher titers of IgG than child sera (P < 0.01). The IgG3 titers to the UspA proteins were higher than the IgG1 titers in the adults' sera, while the IgG1 titers were higher than the IgG3 titers in the children's sera (P < 0.05). The IgG antibodies in the sera from 2-month-old children appeared to be maternally derived, since the mean titer was significantly higher than that in sera from 6- to 7-month-old children (P < 0.05). Serum IgA antibodies to both UspA1 and UspA2 were low during the first 7 months of age but thereafter gradually increased along with the IgG titers. Analysis of sera absorbed with UspA1 or UspA2 showed that the antibodies to UspA1 and UspA2 were cross-reactive with each other and associated with serum bactericidal activity. Examination of affinity-purified human antibodies confirmed that naturally acquired antibodies to UspA1 and UspA2 were bactericidal and cross-reactive. These results support using UspA1 and UspA2 in a vaccine to prevent M. catarrhalis infections.  (+info)

Expression of the plague plasminogen activator in Yersinia pseudotuberculosis and Escherichia coli. (7/8526)

Enteropathogenic yersiniae (Yersinia pseudotuberculosis and Yersinia enterocolitica) typically cause chronic disease as opposed to the closely related Yersinia pestis, the causative agent of bubonic plague. It is established that this difference reflects, in part, carriage by Y. pestis of a unique 9.6-kb pesticin or Pst plasmid (pPCP) encoding plasminogen activator (Pla) rather than distinctions between shared approximately 70-kb low-calcium-response, or Lcr, plasmids (pCD in Y. pestis and pYV in enteropathogenic yersiniae) encoding cytotoxic Yops and anti-inflammatory V antigen. Pla is known to exist as a combination of 32.6-kDa (alpha-Pla) and slightly smaller (beta-Pla) outer membrane proteins, of which at least one promotes bacterial dissemination in vivo and degradation of Yops in vitro. We show here that only alpha-Pla accumulates in Escherichia coli LE392/pPCP1 cultivated in enriched medium and that either autolysis or extraction of this isolate with 1.0 M NaCl results in release of soluble alpha and beta forms possessing biological activity. This process also converted cell-bound alpha-Pla to beta-Pla and smaller forms in Y. pestis KIM/pPCP1 and Y. pseudotuberculosis PB1/+/pPCP1 but did not promote solubilization. Pla-mediated posttranslational hydrolysis of pulse-labeled Yops in Y. pseudotuberculosis PB1/+/pPCP1 occurred more slowly than that in Y. pestis but was otherwise similar except for accumulation of stable degradation products of YadA, a pYV-mediated fibrillar adhesin not encoded in frame by pCD. Carriage of pPCP by Y. pseudotuberculosis did not significantly influence virulence in mice.  (+info)

Characterization of Moraxella (Branhamella) catarrhalis lbpB, lbpA, and lactoferrin receptor orf3 isogenic mutants. (8/8526)

Pathogenic members of the family Neisseriaceae produce specific receptors to acquire iron from their host's lactoferrin and transferrin. Recently, putative Moraxella catarrhalis lactoferrin receptor genes and a third open reading frame (lbpB, lbpA, and orf3) were cloned and sequenced. We describe the preliminary characterization of isogenic mutants deficient in LbpB, LbpA, or Orf3 protein.  (+info)

Journal Article: Small-Molecule Transport by CarO, an Abundant Eight-Stranded beta-Barrel Outer Membrane Protein from Acinetobacter Baumannii ...
TY - JOUR. T1 - A set of two monoclonal antibodies specific for the cell surface-exposed 39K major outer membrane protein of Haemophilus influenzae type b defines all strains of this pathogen. AU - Gulig, P. A.. AU - Frisch, C. F.. AU - Hansen, E. J.. PY - 1983. Y1 - 1983. N2 - Six murine plasma cell hybridomas producing monoclonal antibodies (mabs) directed against the 39,000-molecular-weight (39K) major outer membrane protein of Haemophilus influenzae type b were employed in the antigenic analysis of the 39K protein. The initial characterization of the mabs by radioimmunoprecipitation analysis showed that four of these mabs reacted with antigenic determinants of the 39K protein that are exposed on the bacterial cell surface and accessible to antibody. The other two mabs reacted with antigenic determinants of the 39K protein that are either not exposed on the H. influenzae type b cell surface or not accessible to antibody (internal determinants). A total of 126 clinical isolates of H. ...
Outer membrane proteins are structurally distinct from those that reside in the inner membrane and play important roles in bacterial pathogenicity and human metabolism. X-ray crystallography studies on |40 different outer membrane proteins have revealed that the transmembrane portion of these proteins can be constructed from either beta-sheets or less commonly from alpha-helices. The most common architecture is the beta-barrel, which can be formed from either a single anti-parallel sheet, fused at both ends to form a barrel or from multiple peptide chains. Outer membrane proteins exhibit considerable rigidity and stability, making their study through x-ray crystallography particularly tractable. As the number of structures of outer membrane proteins increases a more rational approach to their crystallization can be made. Herein we analyse the crystallization data from 53 outer membrane proteins and compare the results to those obtained for inner membrane proteins. A targeted sparse matrix screen for
OprF is a major outer membrane protein from Pseudomonas aeruginosa, a homolog of OmpA from Escherichia coli. The N-terminal domains of both proteins have been demonstrated to form low conductance channels in lipid bilayers. Homology models, consisting of an eight-stranded beta-barrel, of the N-terminal domain OprF have been constructed based on the crystal structure of the corresponding domain from E. coli OmpA. OprF homology models have been evaluated via a set (6 x 10 ns) of simulations of the beta-barrel embedded within a solvated dimyristoyl-phosphatidylcholine (DMPC) bilayer. The conformational stability of the models is similar to that of the crystal structure of OmpA in comparable simulations. There is a degree of water penetration into the pore-like center of the OprF barrel. The presence of an acidic/basic (E8/K121) side-chain interaction within the OprF barrel may form a gate able to close/open a central pore. Lipid-protein interactions within the simulations were analyzed and revealed that
A vast number of studies have been completed on the virulence determinants of Yersinia spp.; however, the focus of many of these studies has been on the virulence plasmid and the plasmid-encoded Type three secretion system. Nevertheless, many chromosomal genes whose products are directly involved in virulence have also been identified. Some of these critical virulence determinants are outer membrane proteins. Outer membrane proteins of Gram-negative bacteria often have important physiological roles; however, some have also been found to be important for pathogenesis. In this thesis, we investigated two Yersinia. pestis outer membrane proteins, Ail and OmpA, and their roles in virulence. We provide evidence that Y. pestis Ail is a highly expressed outer membrane protein that is absolutely essential for Y. pestis to resist the killing action of the complement system present in human blood and tissues, as well as the blood and tissues of other mammalian hosts. Furthermore, Ail was important for ...
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The toxR gene of Vibrio cholerae encodes a transmembrane, DNA-binding protein that activates transcription of the cholera toxin operon and a gene (tcpA) for the major subunit of a pilus colonization factor. We constructed site-directed insertion mutations in the toxR gene by a novel method employing the chromosomal integration of a mobilizable suicide plasmid containing a portion of the toxR coding sequence. Mutants containing these new toxR alleles had an altered outer membrane protein profile, suggesting that two major outer membrane proteins (OmpT and OmpU) might be under the control of toxR. Physiological studies indicated that varying the concentration of the amino acids asparagine, arginine, glutamate, and serine caused coordinate changes in the expression of cholera toxin, TcpA, OmpT, and OmpU. Changes in the osmolarity of a tryptone-based medium also produced coordinate changes in the expression of these proteins. Other environmental signals (temperature and pH) had a more pronounced ...
Drugs and certain proteins are transported across the membranes of Gram-negative bacteria by energy-activated pumps. The outer membrane component of these pumps is a channel that opens from a sealed resting state during the transport process. We describe two crystal structures of the Escherichia coli outer membrane protein TolC in its partially open state. Opening is accompanied by the exposure of three shallow intraprotomer grooves in the TolC trimer, where our mutagenesis data identify a contact point with the periplasmic component of a drug efflux pump, AcrA. We suggest that the assembly of multidrug efflux pumps is accompanied by induced fit of TolC driven mainly by accommodation of the periplasmic component.,br/, ...
Cloning and characterization of the major outer membrane protein gene (ompH) of Pasteurella multocida X-73.: The major outer membrane protein (OmpH) of Pasteure
PCR methods.Holland et al. (31) developed a major outer membrane protein (MOMP)-based PCR test that could identify three species of Chlamydia (C. trachomatis, C. pneumoniae, and C. psittaci) using three primer pairs and one restriction enzyme digestion.. Rasmussen et al. (73) described a protocol that amplifies a conserved genus-specific target of the chlamydial MOMP gene followed by restriction enzyme digestion for species identification.. Watson et al. (89) developed a PCR assay based on amplification of the 60-kDa cysteine-rich outer membrane protein genes of C. psittaci, C. pneumoniae, and C. trachomatis, followed by species differentiation with four restriction endonuclease digestion enzymes. Similarly, Tjhie et al. (84) developed a general PCR with a target within the MOMP gene. Subsequent species-specific differentiation of C. trachomatis, C. pneumoniae, and C. psittaciwas performed by hybridization of the amplified PCR product with internal probes.. Several of the early methods described ...
Molecular dynamics simulations by Department of Biochemistrys Dr Phillip Stansfeld, in the lab of Professor Mark Sansom, have helped to reveal how bacteria construct a barrier against antibiotics and the bodys immune system.
Khandelwal and colleagues succeeded in identifying the insecticidal factor. The active component was found in a large complex normally associated with the bacterial outer membrane, and was also present in or on outer membrane vesicles (OMVs) released from the bacterial surface, says Khandelwal. They then searched through OMV components and identified a small (17 kDa) toxic protein. When purified, this protein was toxic to cultured larval cells and directly killed H. armigera larvae. Gene cloning and sequencing showed this protein is related to a class of bacterial outer membrane proteins that form protrusions, called pili or fimbriae, which often help bacteria attach to host cells during infection. Similar to pili proteins, the purified 17 kDa protein self-associated to form oligomers, each of which was connected to the next by a strand. Most importantly, the recombinant 17 kDa protein killed H. armigera larvae, demonstrating its potential as a biological control agent in a world desperately in ...
Dispensable loops shield the functionally-important extracellular loops of the essential Gram-negative bacterial outer membrane protein LptD from antibody interference.
TY - JOUR. T1 - Asymmetric phospholipid. T2 - Lipopolysaccharide bilayers; a Gram-negative bacterial outer membrane mimic. AU - Clifton, Luke A.. AU - Skoda, Maximilian W. A.. AU - Daulton, Emma L.. AU - Hughes, Arwel V.. AU - Le Brun, Anton P.. AU - Lakey, Jeremy. H.. AU - Holt, Stephen A.. PY - 2013/12/6. Y1 - 2013/12/6. N2 - The Gram-negative bacterial outer membrane (OM) is a complex and highly asymmetric biological barrier but the small size of bacteria has hindered advances in in vivo examination of membrane dynamics. Thus, model OMs, amenable to physical study, are important sources of data. Here, we present data from asymmetric bilayers which emulate the OM and are formed by a simple two-step approach. The bilayers were deposited on an SiO2 surface by Langmuir-Blodgett deposition of phosphatidylcholine as the inner leaflet and, via Langmuir-Schaefer deposition, an outer leaflet of either Lipid A or Escherichia coli rough lipopolysaccharides (LPS). The membranes were examined using ...
p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class=publication>Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href=>Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...
TY - JOUR. T1 - Studies on the region involved in the transport activity of Escherichia coli TolC by chimeric protein analysis. AU - Yamanaka, Hiroyasu. AU - Tadokoro, Satoshi. AU - Miyano, Masaya. AU - Takahashi, Eizo. AU - Kobayashi, Hidetomo. AU - Okamoto, Keinosuke. N1 - Funding Information: This study was supported in part by a grant-in-aid for scientific research (C) from the Ministry of Education, Culture, Sports, Science and Technology, Japan (Grant no. 14570252) and the scientific grant 2006 from Hiroshima International University, Japan (Project no. 9905833).. PY - 2007/5. Y1 - 2007/5. N2 - Gram-negative bacteria possess the outer membrane protein TolC which acts as an exit duct across the outer membrane. However, the region involved in the transport activity of TolC has remained unclear. We analyzed this region by creating chimeric TolCs. First, we expressed the genes for TolCs of Vibrio parahaemolyticus (vp-tolC) and Salmonella typhimurium (sal-tolC) in Escherichia coli. The levels ...
Bacterial OMPs are synthesized in the cytosol as precursor proteins with an amino‐terminal signal sequence that guides the proteins to the Sec machinery for crossing the inner membrane and is cleaved off in the periplasm. Periplasmic chaperones then escort OMPs through the aqueous periplasmic space in a partly unfolded state. On reaching the outer membrane, OMPs assemble into a β‐barrel structure and insert into the outer membrane with the help of the BAM complex. The bacterial OMP insertion pathway can be compared to the assembly pathway of MBOMPs from the mitochondrial intermembrane space into the outer membrane. MBOMPs are synthesized in the cytosol and imported into the intermembrane space by the outer membrane translocator TOM40. The subsequent chaperone‐mediated escort across the intermembrane space and insertion into the outer membrane by the TOB complex is similar to the OMP assembly process. Notably, the BAM and TOB complexes share the homologous β‐barrel proteins BamA and ...
Tohidi, F. and Teymournejad, O. and Taravati, A. and Al Ahmadi, K. J. and Rajabnia, R. (2015) Analysis of important H.pylori Outer membrane proteins by detection of common sequences in exposed areas; in silico study. Biosciences Biotechnology Research Asia, 12. pp. 135-143. Tohidi, F. and Teymournejad, O. and Taravati, A. and Al Ahmadi, K. J. and Rajabnia, R. (2015) Analysis of important H.pylori Outer membrane proteins by detection of common sequences in exposed areas; in silico study. Biosciences Biotechnology Research Asia, 12. pp. 135-143. ...
Antigen 43 is a unique autotransporter that promote bacterial cell-to-cell aggregation. Antigen 43 can be expressed on the E.coli cell surface in large quantities, up to 50000 copies per cell.[1] The structure analysis of antigen 43 revealed that antigen 43 has an N-terminal signal peptide; an N-proximal passenger domain that is secreted, which could also be called α domain; an autochaperone domain that facilitates folding of the passenger domain; and a C-terminal β-barrel domain that forms an integral outer membrane protein, also called β domain[2]. The passenger domain(αdomain) confers the autoaggregation phenotype and it is bound to the surface via non-covalent interaction with the βdomain. ...
Proteins can be immobilised on surfaces to make arrays with potential uses in tissue engineering, proteomics and point of use diagnostic devices. Outer membrane proteins (OMP) from Escherichia coli have a beta-barrel structure, making ideal protein engineering scaffolds for building arrays. The proteins can be immobilised onto flat gold surfaces by introducing a cysteine residue into their periplasmic turns. The thiol group of the cysteine will form a strong gold-thiolate bond immobilising the OMP to the surface in a specific and correct orientation. The membrane layer is completed by the immobilisatin of a lipid with a thiol head group to the gold surface. Here we use the transmembrane section of the monomeric protein OmpA (TmOmpA). The Z domain of Staphylococcus aureau protein A has been engineered into the N - terminal of a circularly permuted TmOmpA to create the protein ZZctOmpA. The Z domain can bind immunoglobulin G (IgG) at its constant region leaving the variable regions free to bind ...
The gram-negative bacterial envelope is a complex extracytoplasmic compartment responsible for numerous cellular processes. Among its most important functions is its service as the protective layer separating the cytoplasmic space from the ever-changing external environment. To adapt to the diverse conditions encountered both in the environment and within the mammalian host, Escherichia coli and Salmonella species have evolved six independent envelope stress response systems . This review reviews the sE response, the CpxAR and BaeSR two-component systems (TCS) , the phage shock protein response, and the Rcs phosphorelay system. These five signal transduction pathways represent the most studied of the six known stress responses. The signal for adhesion to abiotic surfaces enters the pathway through the novel outer membrane lipoprotein NlpE, and activation on entry into the exponential phase of growth occurs independently of CpxA . Adhesion could disrupt NlpE causing unfolding of its unstable N-terminal
Author: Anbazhagan, V. et al.; Genre: Journal Article; Published in Print: 2008-06-10; Title: Incorporation of outer membrane protein OmpG in lipid membranes: protein−lipid interactions and β-barrel orientation.
Allison, Heather, Smith, Darren, Loughnane, Paul, Saunders, Jon and McCarthy, Alan (2004) Identification of an outer membrane protein that enables infection of Escherichia coli by Shiga toxin encoding bacteriophage. In: 155th Society for General Microbiology Meeting, September 2004, Dublin, Ireland. Full text not available from this repository. (Request a copy ...
Danese, P.L., Pratt, L.A., Dove, S.L. and Kolter, R. (2000) The Outer Membrane Protein, Antigen 43, Mediates Cell-to-Cell Interactions within Escherichia coli Biofilms. Molecular Microbiology, 37, 424-432.
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We compare several spectral domain based clustering methods for partitioning protein sequence data. The main instrument for this exercise is the spectral density ratio model, which specifies that the logarithmic ratio of two or more unknown spectral density functions has a parametric linear combination of cosines. Maximum likelihood inference is worked out in detail and it is shown that its output yields several distance measures among independent stationary time series. These similarity indices are suitable for clustering time series data based on their second order properties. Other spectral domain based distances are investigated as well; and we compare all methods and distances to the problem of producing segmentations of bacterial outer membrane proteins consistent with their transmembrane topology. Protein sequences are transformed to time series data by employing numerical scales of physicochemical parameters. We also present interesting results on the prediction of transmembrane ...
Subunit Of Both The ERMES And The SAM Complex; Component Of ERMES Complex Which Acts As A Molecular Tether Between The Mitochondria And The ER, Necessary For Efficient Phospholipid Exchange Between Organelles And For Mitophagy; SAM/TOB Complex Component That Functions In The Assembly Of Outer Membrane Beta-barrel Proteins; Involved In Mitochondrial Inheritance And Morphology; ERMES Complex Is Often Co-localized With Peroxisomes And Concentrated Areas Of Pyruvate Dehydrogenase
The mitochondrial outer membrane plays a crucial role in the biogenesis, inheritance and dynamics of the organelle and forms the functional and signaling link between mitochondria and the rest of the eukaryotic cell. This membrane contains a diverse set of proteins that are synthesized in the cytosol and harbor signals that are essential for their subsequent import into mitochondria. We investigate the molecular mechanisms by which the various mitochondrial outer membrane proteins are targeted to mitochondria, inserted into the outer membrane and assembled into functional complexes within the membrane. In addition, we study the mechanisms and components that regulate lipids homeostasis in mitochondria. For our studies we use both yeast and mammalian tissue cultures as experimental systems.. ...
The mitochondrial outer membrane plays a crucial role in the biogenesis, inheritance and dynamics of the organelle and forms the functional and signaling link between mitochondria and the rest of the eukaryotic cell. This membrane contains a diverse set of proteins that are synthesized in the cytosol and harbor signals that are essential for their subsequent import into mitochondria. We investigate the molecular mechanisms by which the various mitochondrial outer membrane proteins are targeted to mitochondria, inserted into the outer membrane and assembled into functional complexes within the membrane. In addition, we study the mechanisms and components that regulate lipids homeostasis in mitochondria. For our studies we use both yeast and mammalian tissue cultures as experimental systems.. ...
Nair, S A and Rathinavelan, Thenmalarchelvi (2015) Bidirectional water conductivity of E.coli outer membrane lectin(Wzi) is regulated by surface aromatic residues and luminal hydrophobic plug. In: National Symposium on Biophysics and Golden Jubilee Meeting of Indian Biophysical Society, Center for Interdisciplinary Research in Basic Sciences, 14-17 February 2015, New Delhi, India. Full text not available from this repository. (Request a copy ...
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Bacterial proteins with MCE domains were first described as being important for Mammalian Cell Entry. More recent evidence suggests they are components of lipid ABC transporters. In Escherichia coli, the single-domain protein MlaD is known to be part of an inner membrane transporter that is important for maintenance of outer membrane lipid asymmetry. Here we describe two multi MCE domain-containing proteins in Escherichia coli, PqiB and YebT, the latter of which is an orthologue of MAM-7 that was previously reported to be an outer membrane protein. We show that all three MCE domain-containing proteins localise to the inner membrane. Bioinformatic analyses revealed that MCE domains are widely distributed across bacterial phyla but multi MCE domain-containing proteins evolved in Proteobacteria from single-domain proteins. Mutants defective in mlaD, pqiAB and yebST were shown to have distinct but partially overlapping phenotypes, but the primary functions of PqiB and YebT differ from MlaD. Complementing
Syma Khalid (Investigator) Many bacteria have an outer membrane which is the interface between the cell and its environment. The components of this membrane are well studied at an individual level, but there is a need to model and understand the outer membrane as a whole. In this project we aim to develop such a model of a bacterial outer membrane, linking computer simulations of the component molecules through to a more systems biology approach to modelling the outer membrane as a whole. Such an approach to modelling an OM must be multi-scale i.e. it must embrace a number of levels ranging from atomistic level modelling of e.g. the component proteins through to higher level agent-based modelling of the interplay of multiple components within the outer membrane as a whole. The different levels of description will be integrated to enable predictive modelling in order to explore the roles of outer membrane changes in e.g. antibiotic resistance.. ...
The relationship between iron acquisition and microbial pathogenesis (1, 38, 51, 84, 104) underscores the importance of the role of TonB in cell envelope physiology. Passage of ferric complexes through the OM requires TonB activity, and one theory of this requirement is that TonB participates in transport energetics by capturing proton motive force from the IM (where its N terminus resides) and distributing it to the OM transporters (14, 23, 76, 82, 95). According to the shuttle model of TonB action, it associates with the IM proteins ExbB and ExbD (42, 56), acquires proton motive force-generated energy by an unknown structural transition, and transmits (15) or physically transports (55, 57) the energy across the periplasm to the OM. The proposed interaction of energized TonB with OM proteins entails recognition of ligand-bound receptors and release of the stored force to them by protein-protein interactions between the C-terminal residues of TonB and the TonB box sequence of the LGP (76, ...
We describe a lesion, lamB701-708, affecting the hydrophilic portion of the lambda receptor signal sequence. The C to A transversion of the sixth codon of the signal sequence changes a positively charged arginine to a neutral serine. The phenotype conferred by this alteration is unique among previously described signal sequence mutations. The results suggest an essential role for the charged amino acids of the hydrophilic segment in the initial interaction between a nascent secreted protein and a membrane export site. The results further suggest that synthesis of lambda receptor is coupled to its export ...
The outer membrane of most Gram-negative bacteria is made up of LPS, and in nearly all bacteria that contain LPS it is essential for the life of the organism. The lipid portion of this molecule, lipid A, also known as endotoxin, is a potent activator of the innate immune response. More than 50 genes are required to synthesize LPS and assemble it at the cell surface. Enormous progress has been made in elucidating the structure and biosynthesis of LPS, but until recently the cellular components required for its transport from its site of synthesis in the inner membrane to its final cellular location at the cell surface remained elusive. Here we describe the identification of a protein complex that functions to assemble LPS at the surface of the cell. This complex contains two proteins: Imp, already identified as an essential outer-membrane protein implicated in LPS assembly; another protein, RlpB, heretofore identified only as a rare lipoprotein. We show that RlpB is also essential for cell viability and
The [email protected] Centre provides a platform for research students to deposit their Ph.D. theses and make it available to the entire scholarly community in open access. Shodhganga Mirror Site ...
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CPn0444 is similar to CT871, CT874, CT413, CT812, CT872, CT414, CT412, CT870, CT869, and CT456. They are predicted outer membrane proteins. CT871 is a predicted pmpG outer membrane protein G. Residues 470-1407 are 28% similar to CT871 ...
22, Table 33. Their outer membrane proteins contain cross- reactive antigens and surface-exposed epitopes that are species specific.
An outer membrane protein T (OmpT) could play a vital role in the pathogenesis of the neonatal meningitis Escherichia coli (NMEC) in human and animals. However, whether ompT plays a role in avian pathogenic E. coli (APEC) infection remains unclear. In this study we evaluated the potential of ompT in APEC pathogenesis. An ompT gene was deleted from APEC mutant strain (TW-XM) was constructed and cha ...
sample_1: KpOmpA transmembrane domain, [U-13C; U-15N; U-2H], 1 mM; DHPC 300 mM; NaH2PO4 20 mM; NaCl 100 mM; H2O 90%; D2O 10%. sample_2: KpOmpA transmembrane domain, [U-13C; U-15N; U-2H]/[L,V,I(delta1)-13CH3], 1 mM; DHPC 300 mM; NaH2PO4 20 mM; NaCl 100 mM; H2O 90%; D2O 10%. sample_3: KpOmpA transmembrane domain, [U-15N; 10% 13C], 1 mM; DHPC 300 mM; NaH2PO4 20 mM; NaCl 100 mM; H2O 90%; D2O 10%. sample_4: KpOmpA transmembrane domain, [U-13C; U-15N; U-2H]/[L,V,I(delta1)-13CH3], 1 mM; DHPC 300 mM; NaH2PO4 20 mM; NaCl 100 mM; H2O 90%; D2O 10%. sample_conditions_1: ionic strength: 0.1 M; pH: 6.5; pressure: 1 atm; temperature: 313 K ...
The 5C outer membrane protein, one of the N. meningitidis class 5 proteins, was preferably expressed in bacteria isolated from the nasopharynx and its role in adhering to the mucosal cells and invading them as well as the development of anti-5C antibodies in healthy carriers was demonstrated.... mehr ...
Michalik, M.; Orwick-Rydmark, M.; Habeck, M.; Alva, V.; Arnold, T.; Linke, D.: An evolutionarily conserved glycine-tyrosine motif forms a folding core in outer membrane proteins. PLoS One 12 (8) (2017 ...
View Notes - cells2 from BIOL 20204 at TCU. II. The Cell- Basic Unit of Life A. Cell or Plasma membrane-found @ outer surface of cell 1. Structure i. Thickness-75 ancryms=3/10,000,000 ii. Fluid
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Antigenic determinants were identified from seven chlamydial major outer membrane proteins by using overlapping hexapeptides and polyclonal antisera. Sixty-one determinants were detected, and 30 were surface exposed on the native organisms. The two negatively charged residues, aspartic acid and glutamic acid, were found most often in determinants. Thirteen antigenic sites were further characterized by alanine substitution. Differences in fine specificities of these linear determinants were observed in alanine substitution profiles. Five determinants had adjacent critical residues, while eight had critical residues alternated with noncritical residues. Complete replacement analysis of two antigenic determinants provided more detailed information for elucidating the structural basis of the specificity of antigen-antibody interaction and suggested a correlation between sequence conservation and tolerance to amino acid substitution for antigenic sites subject to intense immune selection pressure. ...
Acinetobacter baumannii is nowadays a relevant nosocomial pathogen characterized by multidrug resistance (MDR) and concomitant difficulties to treat infections. OmpA is the most abundant A. baumannii outer membrane (OM) protein, and is involved in virulence, host-cell recognition, biofilm formation, regulation of OM stability, permeability and antibiotic resistance. OmpA members are two‐domain proteins with an N‐terminal eight‐stranded β‐barrel domain with four external loops (ELs) interacting with the environment, and a C‐terminal periplasmic domain binding non‐covalently to the peptidoglycan. Here, we combined data from genome sequencing, phylogenetic and multilocus sequence analyses from 975 strains/isolates of the Acinetobacter calcoaceticus/Acinetobacter baumannii complex (ACB), 946 from A. baumannii, to explore ompA microevolutionary divergence. Five major ompA variant groups were identified (V1 to V5) in A. baumannii, encompassing 52 different alleles coding for 23 different ...
A murine immunoglobulin G monoclonal antibody (MAb) raised against outer membrane vesicles of Moraxella catarrhalis 035E was shown to bind to a surface-exposed epitope of a major outer membrane protein of this organism. This outer membrane protein, which had an apparent molecular weight of approximately 80,000 in sodium dodecyl sulfate-polyacrylamide gels, was designated CopB. MAb 10F3, reactive with CopB, bound to a majority (70%) of M. catarrhalis strains tested. More importantly, mice passively immunized with MAb 10F3 exhibited an enhanced ability to clear a bolus challenge of M. catarrhalis from their lungs, a result which suggested that CopB might have potential as a vaccine candidate. The M. catarrhalis gene encoding CopB was cloned in Escherichia coli, and nucleotide sequence analysis of the copB gene indicated that the CopB protein was synthesized with a leader peptide, a finding confirmed by N-terminal amino acid sequence analysis of the mature CopB protein purified from M. catarrhalis ...
The signal peptide of the outer membrane lipoprotein (OMLP) of Escherichia coli was shown to be capable of promoting protein translocation across mammalian microsomal membranes in vitro. We assayed translocation of a fusion protein containing the OMLP signal peptide and nine amino acids of OMLP fused in frame to beta-lactamase. The efficiency with which the mammalian translocation machinery recognizes and accepts the OMLP signal peptide as substrate is indistinguishable from that of mammalian secretory proteins. Upon translocation mammalian signal peptidase processes the pre-OMLP-beta-lactamase protein at different sites than are utilized in vivo by E. coli OMLP signal peptidase (signal peptidase II) but that can be predicted as mammalian signal peptidase cleavage sites. Mutants in the OMLP signal peptide were tested for their ability to promote translocation of the fusion protein in this assay system. It has been shown previously that mutants in the positively charged amino acids at the amino ...
rdf:RDF xmlns:dcterms= xmlns:dc= xmlns:rdf= xmlns:bibo= xmlns:dspace= xmlns:foaf= xmlns:void= xmlns:xsd= , ,rdf:Description rdf:about=, ,dspace:isPartOfCollection rdf:resource=, ,dc:creator,Qu, Jian,/dc:creator, ,dc:contributor,Holst, Otto,/dc:contributor, ,foaf:homepage rdf:resource=http://localhost:8080/jspui/, ,dcterms:abstract xml:lang=eng,Periplasmic Skp facilitates folding and membrane insertion of many outer membrane proteins (OMPs) into the outer membrane of Gram-negative bacteria. We have examined the binding sites of outer membrane protein A (OmpA) from Escherichia coli in its complexes ...
Part of the outer membrane protein assembly complex, which is involved in assembly and insertion of beta-barrel proteins into the outer membrane. Constitutes, with BamD, the core component of the assembly machinery.
The availability of genome sequences and the corresponding translated protein databases have enabled studies on the meningococcal proteome, particularly the detailed composition of outer membrane fractions. In early studies, Frasch and colleagues [20] were able to distinguish only five major classes of proteins in outer membrane preparations from meningococci. Subsequently, additional proteins were identified that were present in lower amounts or only expressed when the bacteria had been grown under nutrient limitation (reviewed in [21]). The total number of proteins identified in outer membrane preparations remained relatively few until the development of more sensitive proteomic methods. This combined with the availability of the translated genome sequences has enabled much more detailed study of outer membrane preparations and the vesicle/vaccine preparations derived from them by deoxycholate extraction. One-dimensional SDS-PAGE of an OMV vaccine preparation followed by tandem mass ...
Outer membrane porin D is a protein family containing bacterial outer membrane porins which are involved in transport of cationic amino acids, peptides, antibiotics and other compounds. It was also described as having some serine protease activity. However many of these proteins are not peptidases and are classified as non-peptidase homologues as they either have been found experimentally to be without peptidase activity, or lack amino acid residues that are believed to be essential for the catalytic activity of peptidases in the S43 family. Yoshihara E, Yoneyama H, Ono T, Nakae T (June 1998). Identification of the catalytic triad of the protein D2 protease in Pseudomonas aeruginosa. Biochem. Biophys. Res. Commun. 247 (1): 142-5. doi:10.1006/bbrc.1998.8745. PMID 9636669. This article incorporates text from the public domain Pfam and InterPro ...
No information on the cytokine profile to be used as a marker of Campylobacter jejuni infection protection. For this study, we used the outer membrane protein (MOMP [Pora]) as a vaccine for the protection and spleen cell cytokine as a marker of protection. We cloned and expressed Pora from C. jejuni111 and mice immunized with intraperitoneal route. Subsequently, the mice orally challenged with C. jejuni 111. live vaccine-induced protection as evidenced by a decrease in fecal excretion C. jejuni111. Cytokines were measured in vitro after stimulation of spleen cells with MOMP. Levels of pro-inflammatory cytokines, IL-12, TNF-α, IL-17A and IL-17F are similar in the control and test mice. Levels of pro-inflammatory cytokines, IL-2 and IFN-γ were higher in mice than in control mice test, and the level of pro-inflammatory cytokines, IL-8 and IL-1β was higher in the test mice than in control mice. In between the two anti-inflammatory cytokines, the same level of IL-10 but higher for IL-4 in the test ...
In this study pore forming proteins of the gram-negative bacteria B. burgdorferi, B. duttonii and E.coli were investigated. Therefore the study is subdivided into three parts. In the first part outer membrane preparation of three relapsing fever Borrelia were investigated. In the second part the putative TolC homologue BB0124 of B. burgdorferi, the Lyme borreliosis agent, was studied. In the last part the influence of point mutants within the greasy slide of the maltose specific porin (LamB) of E. coli were shown. In the first part of this study outer membrane preparations of three Borrelia relapsing fever strains have been studied for pore-forming activity in the black lipid bilayer assay. Histograms of conductance fluctuations were obtained from single-channel experiments with outer membrane preparations of B. hermsii, B. recurentis and B. duttonii. All strains had a different conductance fluctuation pattern with a broad range of single-channel conductance values varying from 0.5 nS - 11 nS. ...
The Tar chemoreceptor of Escherichia coli is a membrane-bound sensory protein that facilitates bacterial chemotaxis in response to aspartate. The EnvZ molecule has a membrane topology similar to Tar and is a putative osmosensor that is required for osmoregulation of the genes for the major outer membrane porin proteins, OmpF and OmpC. The cytoplasmic signaling domain of Tar was replaced with the carboxyl portion of EnvZ, and the resulting chimeric receptor activated transcription of the ompC gene in response to aspartate. The activation of ompC by the chimeric receptor was absolutely dependent on OmpR, a transcriptional activator for ompF and ompC. ...
Gonorrheal urethritis was induced in three males by intraurethral instillation of predominantly pilus+ protein II- gonococci. Virtually all gonococci reisolated from the infected men exhibited protein II+ phenotype. The reisolated gonococci expressed five distinct outer membrane protein II species. Protein IIc+ organisms predominated in urines of all three subjects, but variants expressing this particular protein II were rarely spawned in vitro by input organisms. Protein IIc+ gonococci appeared early in one mans infection; they were joined later by variants that displayed eight other protein II phenotypes, including protein II-. These results show that input protein II- gonococci are supplanted by protein IIc+ variants during incipient gonorrheal urethritis. As infection progresses, a broader variety of protein II+ variants appears. ...
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PubMed journal article Export of the outer membrane lipoprotein is defective in secD, secE, and secF mutants of Escherichia col were found in PRIME PubMed. Download Prime PubMed App to iPhone or iPad.
Bacteria outer membrane lipoprotein I: vaccine candidate; antigenically cross-reacts with all serotype strains of the International Antigenic Typing Scheme; amino acid sequence given in first source
Lipoprotein NlpI of Escherichia coli is involved in the cell division, virulence, and bacterial interaction with eukaryotic host cells. To elucidate the functional mechanism of NlpI, we examined how NlpI affects cell division and found that induction of NlpI inhibits nucleoid division and halts cell growth. Consistent with these results, the cell division protein FtsZ failed to localize at the septum but diffused in the cytosol. Elevation of NlpI expression enhanced the transcription and the outer membrane localization of the heat shock protein IbpA and IbpB. Deletion of either ibpA or ibpB abolished the effects of NlpI induction, which could be restored by complementation. The C-terminus of NlpI is critical for the enhancement in IbpA and IbpB production, and the N-terminus of NlpI is required for the outer membrane localization of NlpI, IbpA, and IbpB. Furthermore, NlpI physically interacts with IbpB. These results indicate that over-expression of NlpI can interrupt the nucleoids division and the
Genome analysis identified a large number of genes that would enable utilization of dilute carbon sources and provides a comprehensive picture of the strategies used by C. crescentus for survival in nutrient-limiting conditions. Unlike E. coli and Vibrio cholerae, C. crescentus has no OmpF-type outer membrane porins that allow the passive diffusion of hydrophilic substrates across the outer membrane. However, it does possess 65 members of the family of TonB-dependent outer membrane channels that catalyze energy-dependent transport across the outer membrane. This is more than any other organism thus far characterized, with the next highest being 34 in Pseudomonas aeruginosa (32), and with no other sequenced proteobacteria possessing more than 10. C. crescentus has substantially fewer cytoplasmic membrane transporters relative to genome size than either E. coli or V. cholerae (33). Given C. crescentus low nutrient habitat, it is surprising that PTS or ATP-binding cassette domain transporters, ...
A mutant variant of a septicemic Escherichia coli strain (L3) isolated from an outbreak in chickens was constructed by the insertion of TnphoA transposon. Seven mutant derivatives were analyzed regarding the pathogenicity. Two of them (XP2, XP4) were less pathogenic in the one-day-old chick pathogenicity assay. The expression of several outer membrane proteins of mutant XP2 strain was suppressed, and strain XP4 had a 47.8(kDa) protein that was not expressed. None of these proteins was correlated to the iron-acquisition system. Mutant XP2 could have suppression of a regulatory protein responsible for the expression of other proteins not related to pathogenicity but important for the rapid bacterial growth, while mutant XP4 did not express a 47.8(kDa) protein. We propose that the 47.8(kDa) protein could be associated to the pathogenicity process of Escherichia coli strains responsible for septicemia in poultry ...
The structural and functional differences between wild type (WT) outer membrane protein G and its two mutants are investigated with Fourier transform infrared spectroscopy. Both mutants have a long extension to the primary sequence to increase the number of beta-strands from 14 (wild type) to 16 in an attempt to enlarge the pore diameter. The comparison among proteins is made in terms of pH-dependent conformational changes and thermal stability. Results show that all proteins respond to pH change but at different degrees. At acidic environment, all proteins contain the same number of residues participated in beta-sheet structure. However, at neutral pH, the mutants have less ordered structure compared to WT porin. Thermal stability tests show that mutants differ significantly from WT porin at neutral pH. Although the transition temperature is directly proportional with the amount of beta-sheet content, the changes in the pre-transition phase that pave the way to structural breakdown are shown to ...
The membrane assembly of outer membrane proteins is more complex than that of transmembrane helical proteins owing to the intervention of many charged and polar residues in the membrane. Accordingly, the predictive accuracy of transmembrane beta strands is considerably lower than that of transmembrane alpha helices. In this paper we develop a set of conformational parameters for membrane spanning beta strands. We formulate an algorithm to predict the transmembrane beta strands in the family of bacterial porins based on the conformational parameters and surrounding hydrophobicities of amino acid residues. A Fortran program has been developed which takes the amino acid sequence as the input file and gives the predicted transmembrane beta strand as output. The present method predicts at an accuracy level of 82% for all the bacterial porins considered.
The susceptibility of the E. coli B strain to a variety of stressful conditions and antibiotics revealed by PM tests (Figure S3 in Additional file 1) can be explained by several observations (Figure 5). First, differences in the composition of the LPS core and expression of outer membrane proteins may influence the permeability and integrity of the cell envelope. B strains produce more OmpF porin than K-12 strains because the B genome lacks micF, which post-transcriptionally prevents production of OmpF [24]. This is further supported by the transcriptome data showing high levels of ompF expression in the B strain and high expression of ompC and ompA in the K-12 strain (Figure 4). These observations were also consistent with results of proteome analysis of the outer membrane fractions (Figure S2B in Additional file 1). Noxious agents such as antibiotics and bile acids diffuse more easily through OmpF than OmpC because the former produces a channel with a larger pore size [25]. Second, synthesis ...
Pseudomonas aeruginosa is an important cause of nosocomial infection and may lead to septicemia and death. P. aeruginosa septicaemia is associated with the highest mortality rate of all gram-negative infections. Because of the general resistance of the organism to antibiotics, research has been focused on immunotherapy. There are several bacterial cell components incorporated into subunit vaccines. Vaccine studies have often focussed on Lipo Poly Saccharide (LPS) and the outer membrane proteins (OPRs) due to its potent stimulation of the immune response. The pathophysiological nature of LPS and its serotype-specific immunological activities has limited LPS using for Pseudomona infection control whereas using major Outer Membrane Proteins of cell walls (mOMPs) of Pseudomonas aeruginosa and other gram-negative bacteria, not only is non-toxic and actively stimulate the immune system but also shows immunological cross-reactivity with mOMPs of other serotypes belonging to same species. Today, the ...
Protein TonB; Interacts with outer membrane receptor proteins that carry out high-affinity binding and energy dependent uptake into the periplasmic space of specific substrates. It could act to transduce energy from the cytoplasmic membrane to specific energy- requiring processes in the outer membrane, resulting in the release into the periplasm of ligands bound by these outer membrane proteins (249 aa ...
In the present study, antigenic cross-reactivity of OMPs was investigated in several species of bacterial pathogens. Heterogeneous mouse or fish antisera were used to ascertain OMPs with cross-reactivity and cluster analysis was performed to analyze the distribution of cross-antigenic OMPs in diverse bacterial strains. We interestingly found that eleven and seven bands could be reacted with four kinds of heterogeneous mouse and fish antisera, respectively, and the phenograms constructed could provide ideal targeted bacteria for candidate genes of polyvalent vaccines. Importantly, there were significant differences in reaction with bacteria between mouse and fish antisera, but commonly antigenic bands still existed between them. Our results suggest that the cross-reactivity of OMPs exists commonly in Gram-negative bacteria, which may be a promising choice for the development of polyvalent OMP vaccines. Meanwhile, cluster analysis will help to understand the relation of cross-antigenic OMPs among ...
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Motivation: Transmembrane beta-barrels exist in the outer membrane of gram-negative bacteria as well as in chloroplast and mitochondria. They are often involved in transport processes and are promising antimicrobial drug targets. Structures of only a few beta-barrel protein families are known. Therefore, a method that could automatically generate such models would be valuable. The symmetrical arrangement of the barrels suggests that an approach based on idealized geometries may be successful. Results: Here, we present tobmodel; a method for generating 3D models of beta-barrel transmembrane proteins. First, alternative topologies are obtained from the BOCTOPUS topology predictor. Thereafter, several 3D models are constructed by using different angles of the beta-sheets. Finally, the best model is selected based on agreement with a novel predictor, ZPRED3, which predicts the distance from the center of the membrane for each residue, i.e. the Z-coordinate. The Z-coordinate prediction has an average ...
Specific assembly proteins are required for the folding and integration of autotransporters into the outer membrane. Employing x-ray crystallography, the authors of the study decoded the atomic structure of the autotransporter assembly protein TamA of the intestinal bacterium Escherichia Coli.. The protein TamA, explains Fabian Gruss, first author and recipient of a Werner-Siemens PhD fellowship, also forms a barrel with a pore. The pore is closed to the outside by a lid but a particular kink in the barrel wall provides a gate for autotransporter substrates. When an unfolded autotransporter is delivered, TamA hooks onto one end of the substrate polypeptide chain and integrates it step by step via the gate into its own barrel structure. The TamA barrel is thus expanded; the pore widens and opens such that passenger substrates traverse to the exterior. The assembly process ends when TamA releases the autotransporter into the surrounding membrane. The autotransporter insertion mechanism was ...
Structural relatedness of enteric bacterial porins assessed with monoclonal antibodies to Salmonella typhimurium OmpD and OmpC.: The immunochemistry and structu
1.B.55 The Poly Acetyl Glucosamine Porin (PgaA) Family. The linear homopolymer poly-beta-1,6-N-acetyl-D-glucosamine (beta-1,6-GlcNAc; PGA) serves as an adhesin for the maintenance of biofilm structural stability in diverse eubacteria. Its function in Escherichia coli K-12 requires the gene products of the pgaABCD operon, all of which are necessary for biofilm formation. PgaC is an apparent glycosyltransferase that is required for PGA synthesis, and PgaD is also needed for PGA formation. Deletion of genes for the predicted outer membrane proteins PgaA and PgaB did not prevent PGA synthesis but did block its export at the cell poles, the initial attachment site for biofilm formation (Itoh et al., 2008). PgaA contains a predicted beta-barrel porin and a superhelical domain containing tetratricopeptide repeats, which may mediate protein-protein interactions. It may form the outer membrane secretin for PGA. PgaB contains predicted carbohydrate binding and polysaccharide N-deacetylase domains. ...
The periplasm (the space between the inner and outer membranes of bacteria) is the site of activation of the periplasmic stress response. Like the cytosolic stress response and the eukaryotic endoplasmic and cytosolic stress responses, unfolded proteins trigger a transcriptional activation profile that allows cells to produce more chaperones and protein-folding agents (see Young and Hartl). Although, the periplasmic stress response is fairly well characterized, the sensor that initiates the process has remained elusive. The response consists of activation of the protease DegS, which cleaves transmembrane protein RseA, which then releases the transcription factor σE to allow the activation of stress response genes. Walsh et al. show that DegS is inhibited by its PDZ domain and that binding of the PDZ domain toYQF motifs of outer membrane protein porins activates the protease. Bacteria expressing DegS lacking the PDZ domain showed increased σE activity. Using an oriented peptide library, a ...
The outer membrane (OM) of Gram-negative pathogenic bacteria represents a platform for the secretion and presentation of surface-localized virulence factors. Th...
Abstract: The β-barrel assembly machinery (BAM) inserts outer membrane β-barrel proteins (OMPs) in the outer membrane of Gram-negative bacteria. In Enterobacteriacea, BAM also mediates export of the stress sensor lipoprotein RcsF to the cell surface by assembling RcsF-OMP complexes. Here, we report the crystal structure of the key BAM component BamA in complex with RcsF. BamA adopts an inward-open conformation, with the lateral gate to the membrane closed. RcsF is lodged deep within the lumen of the BamA barrel, binding regions proposed to undergo outward and lateral opening during OMP insertion. On the basis of our structural and biochemical data, we propose a push-and-pull model for RcsF export following conformational cycling of BamA, and provide a mechanistic explanation for how RcsF uses its interaction with BamA to detect envelope stress. Our data also suggest that the flux of incoming OMP substrates is involved in the control of BAM activity ...
CDS N E->G O3K_21210 sgrR transcriptional regulator SgrR E112/10 4518367 5211133 G->A CDS N A->T O3K_21840 inner membrane protein E112/10 4667748 5061192 G->A CDS N V->I O3K_22600 putative cell envelope opacity-associated protein E112/10 5176186 4552535 C->T CDS N R->H O3K_24910 rffA TDP-4-oxo-6-deoxy-D-glucose transaminase E112/10 174510 4279463.... YjiN / b4336 DUF445 domain-containing protein YjiN from Escherichia coli K-12 substr. MG1655 (see paper ...
1GFN: Structural and functional characterization of OmpF porin mutants selected for larger pore size. I. Crystallographic analysis.
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... s are a family of outer bacterial membrane proteins. These are anion-specific porins, the binding site ...
Irreversible interaction: Bacterial adhesins recognise specific host receptors such as pili and outer membrane proteins. The ... Bacterial transportation: Bacteria will readily adhere to the acquired pellicle through adhesins, proteins and enzymes within ... Cementum is the outer layer of the tooth root; it overlies the dentine layer of the tooth and provides attachment for the ... This results in the imbalance between host and bacterial factors which can in turn result in a change from health to disease. ...
Hritonenko V, Stathopoulos C (2007). "Omptin proteins: an expanding family of outer membrane proteases in Gram-negative ... protein a, Pla, OmpT) are a family of bacterial proteases. They are aspartate proteases, which cleave peptides with the use of ... Found in the outer membrane of gram-negative enterobacteria such as Shigella flexneri, Yersinia pestis, Escherichia coli, and ... Omptins consist of a widely conserved beta barrel spanning the membrane with 5 extracellular loops. These loops are responsible ...
... s (or LamB porins) are bacterial outer membrane proteins of the porin family. Maltoporin forms a trimeric structure ... which facilitates the diffusion of maltodextrins across the outer membrane of Gram-negative bacteria. The membrane channel is ...
... is an evolutionarily conserved domain of bacterial outer membrane proteins. This domain consists ... "The Borrelia afzelii outer membrane protein BAPKO_0422 binds human factor-H and is predicted to form a membrane-spanning β- ... Nair MK, Venkitanarayanan K, Silbart LK, Kim KS (May 2009). "Outer membrane protein A (OmpA) of Cronobacter sakazakii binds ... "Structure of the outer membrane protein A transmembrane domain". Nature Structural Biology. 5 (11): 1013-7. doi:10.1038/2983. ...
... s (KdgM) are a family of outer bacterial membrane proteins from Dickeya dadantii. The ...
The more outer-membrane protein genes that can be expressed, the higher the chance the organism can avoid being recognized by ... Molecular interactions between bacterial symbionts and their hosts Cell, 126 (2006), pp. 453-465 Mavromatis, K.; Doyle, C. K.; ... With a higher range of outer-membrane proteins, the parasite can evade the immune system of the host more effectively and ... The evolutionary changes in the outer membrane proteins have led to the emergence of new strains which can infect a larger ...
In molecular biology, an autotransporter domain is a structural domain found in some bacterial outer membrane proteins. The ... Leo JC, Grin I, Linke D (April 2012). "Type V secretion: mechanism(s) of autotransport through the bacterial outer membrane". ... The protein is directed to the inner membrane by a signal peptide transported across the inner membrane via the Sec machinery. ... The barrel is oriented in the membrane such that the N-terminal portion of the protein, termed the passenger domain, is ...
The comet forms in a polar manner and aids the bacterial migration to the host cell's outer membrane. Gelsolin, an actin ... It induces directed polymerization of actin by the ActA transmembrane protein, thus pushing the bacterial cell around. L. ... Abrishami S. H.; Tall B. D.; Bruursema T. J.; Epstein P. S.; Shah D. B. (1994). "Bacterial adherence and viability on cutting ... Laine R. O.; Phaneuf K. L.; Cunningham C. C.; Kwiatkowski D.; Azuma T.; Southwick F. S. (1 August 1998). "Gelsolin, a protein ...
Bos, Martine P.; Robert, Viviane; Tommassen, Jan (2007). «Biogenesis of the Gram-Negative Bacterial Outer Membrane». Annual ... The recombinant expression systems for structure determination of eukaryotic membrane proteins». Protein & Cell 5 (9): 658. doi ... Sellemembranar kan ha mange protein knytte til seg, og det har vore estimert at 30 % av dei proteinkodande gena i ... Wood, I. Stuart; Trayhurn, Paul (2007). «Glucose transporters (GLUT and SGLT): Expanded families of sugar transport proteins» ( ...
... (the tsx gene of Escherichia coli) is an outer membrane protein, Tsx, which constitutes the receptor ... The protein contains 294 amino acids, the first 22 of which are characteristic of a bacterial signal sequence peptide. Tsx ... which encodes a nucleoside-specific channel-forming protein (Tsx) in the outer membrane of Escherichia coli". Gene. 96 (1): 59- ... shows no significant similarities to general bacterial porins. Bremer E, Martinussen J, Middendorf A, Valentin-Hansen P (1990 ...
However, large proteins must have a specific signaling sequence to be transported across the outer membrane, so the protein ... It is formed as a beta barrel that spans the outer membrane, similar to that in the gram-negative bacterial membrane. Larger ... A mitochondrion contains outer and inner membranes composed of phospholipid bilayers and proteins. The two membranes have ... ATP crosses out through the inner membrane with the help of a specific protein, and across the outer membrane via porins. ADP ...
... or resistance to diffusion across the bacterial outer membrane.[11] Unlike imipenem, it is stable to dehydropeptidase-1, so can ... In general, resistance arises due to mutations in penicillin-binding proteins, production of metallo-β-lactamases, ... It inhibits bacterial cell wall synthesis like other β-lactam antibiotics. In contrast to other beta-lactams, it is highly ... Meropenem, sold under the brandname Merrem among others, is a broad-spectrum antibiotic used to treat a variety of bacterial ...
"Rickettsial Outer-Membrane Protein B (rOmpB) Mediates Bacterial Invasion through Ku70 in an Actin, c-Cbl, Clathrin and Caveolin ... This species of Rickettsia uses an abundant cell surface protein called OmpB to attach to a host cell membrane protein called ... This causes the host cell membrane to protrude outward and invaginate the membrane of an adjacent cell. The bacteria are then ... CDC42, protein tyrosine kinase, phosphoinositide 3-kinase, and Src-family kinases then activate Arp2/3. This causes the ...
... coli where the inner membrane ABC transporter HlyB interacts with an inner membrane fusion protein HlyD and an outer membrane ... some bacterial ABC proteins are also involved in the regulation of several physiological processes. In bacterial efflux systems ... a membrane fusion protein (MFP), and an outer membrane factor (OMF). An example is the secretion of hemolysin (HlyA) from E. ... roles of membrane structure and electrostatics in lipid-protein and protein-protein interactions". Biochimica et Biophysica ...
... that the transport proteins called porins are found in the outer membranes of mitochondria, chloroplasts and bacterial cell ... A membrane lipid cardiolipin is exclusively found in the inner mitochondrial membrane and bacterial cell membranes. Some ... Transport proteins called porins are found in the outer membranes of mitochondria and chloroplasts and are also found in ... The membrane of nuclear envelope and endomembrane vesicles are composed of similar membrane proteins. These vesicles also share ...
Protein TolC, the outer membrane component of a tripartite efflux pump in Escherichia coli. ... Bacterial efflux pumps[edit]. Efflux pumps are proteinaceous transporters localized in the cytoplasmic membrane of all kinds of ... Bacterial efflux transporters are classified into five major superfamilies, based on their amino acid sequence and the energy ... Various natural products have been shown to inhibit bacterial efflux pumps including the carotenoids capsanthin and capsorubin, ...
The OmpW protein contains features similar to a bacterial TonB-linked outer membrane protein which allows the bacteria to ... The TonB-linked outer membrane protein contains a TonB box that is highly conserved and also present in OmpW. OmpW may play a ... B. caccae contains a TonB-linked outer membrane protein called OmpW that has only been characterized in this particular strain ... "Molecular Cloning of a Bacteroides caccae TonB-Linked Outer Membrane Protein Identified by an Inflammatory Bowel Disease Marker ...
... she has explored the development of stochastic biosensors based on bacterial outer membrane proteins and nanopores. In nanopore ... including outer membrane proteins and nucleic acids. Such simulations allow the optimisation and design of synthetic systems ... where she worked alongside Mark Sansom on structure-property relationships of bacterial membrane proteins. Khalid moved to the ... "Coarse-grained MD simulations of membrane protein-bilayer self-assembly". Structure. 16 (4): 621-630. doi:10.1016/J.STR.2008.01 ...
The filled capsids are then coated with the nucleocapsid protein P8, and then outer membrane proteins somehow attract bacterial ... Fusion of the viral envelope with the bacterial outer membrane is facilitated by the phage protein, P6. The muralytic ( ... The spike protein P3 is anchored to a fusogenic envelope protein in P6. P7 is a minor capsid protein, P8 is responsible of ... and the nucleocapsid enters the cell coated with the bacterial outer membrane. A copy of the sense strand of the large genome ...
... a lipoprotein which may form a channel in the bacterial outer membrane. Wzb - a cytoplasmic regulatory phosphatase which ... The CPS operon is likely transcriptionally regulated by the Rcs (regulation of capsule synthesis) proteins. Reduced levels of ... Wzc - a tyrosine kinase found in the bacterial inner membrane. Participates in polymerization of capsule polysaccharides. Wzx ... The CPS operon contains genes which code for the following proteins: Wza - ...
Bacterial effector protein. *Bacterial outer membrane vesicles. *Host-pathogen interface. *Membrane vesicle trafficking ... the formation of bacterial outer membrane vesicles.[26] Portions of the outer membrane pinch off, forming nano-scale spherical ... complex of pore forming secretin proteins. In addition to the secretin protein, 10-15 other inner and outer membrane proteins ... HlyD recruits TolC to the inner membrane and HlyA is excreted outside of the outer membrane via a long-tunnel protein channel. ...
... the ABC protein, membrane fusion protein (MFP), and outer membrane protein (OMP)[specify]. This secretion system transports ... Kuehn, M. J.; Kesty, N. C. (2005). "Bacterial outer membrane vesicles and the host-pathogen interaction". Genes & Development. ... the formation of outer membrane vesicles.[8][9] Portions of the outer membrane pinch off, forming spherical structures made of ... In a channel transupport system, several proteins form a contiguous channel traversing the inner and outer membranes of the ...
In the periplasm a β-barrel domain at the protein's C-terminus inserts into the bacterial outer membrane, forming a channel ... by attaching the protein of interest to a protein which is known to localize to the surface of the bacterial outer membrane. ... These proteins have a signal peptide at the N-terminus which allows them to be translocated across the bacterial inner membrane ... The rest of the protein threads through this channel across the outer membrane and to the surface of the bacteria. Once it ...
The periplasm is a concentrated gel-like matrix in the space between the inner cytoplasmic membrane and the bacterial outer ... Secretion and subcellular localizations of bacterial proteins: a semantic awareness issue. Trends Microbiol. 17:139-145. doi: ... between these membranes. The presence of both inner and outer cell membranes forms and define the periplasmic space or ... all archetypical gram-negative bacteria are bounded by a cytoplasmic membrane as well as an outer cell membrane; they contain ...
The L-ring of the bacterial flagellum is the ring in the lipid outer cell membrane through which the axial filament (rod, hook ... Jones CJ, Homma M, Macnab RM (July 1989). "L-, P-, and M-ring proteins of the flagellar basal body of Salmonella typhimurium: ... gene sequences and deduced protein sequences". J Bacteriol. 171 (7): 3890-3900. doi:10.1128/jb.171.7.3890-3900.1989. PMC 210140 ...
... except for an outer cell membrane. But bacterial microcompartments, which are thought to be simple organelles enclosed in ... Both eukaryotes and prokaryotes contain large RNA/protein structures called ribosomes, which produce protein, but the ribosomes ... It has been suggested that the bacterial order Planctomycetes has a membrane around the nucleoid and contains other membrane- ... The transfer of bacterial DNA is under the control of the bacteriophage's genes rather than bacterial genes. Conjugation in the ...
Within the nuclear membrane, the inner and outer membranes vary in protein composition, and only the outer membrane is ... For example, proteins on the surface of certain bacterial cells aid in their gliding motion.[34] Many gram-negative bacteria ... Proteins. Type. Description. Examples Integral proteins. or transmembrane proteins. Span the membrane and have a hydrophilic ... Membrane proteins consist of three main types: Integral proteins, peripheral proteins, and lipid-anchored proteins.[3] ...
Newly synthesised structural proteins and genomes self-assemble and accumulate near the inside of the cell membrane. Virions ... balance as well as treating any bacterial infections that may develop.[33] Dialysis may be needed for kidney failure, and ... which code for proteins with antiviral properties.[51] EBOV's V24 protein blocks the production of these antiviral proteins by ... This processing appears to allow the virus to bind to cellular proteins enabling it to fuse with internal cellular membranes ...
A protein kinase drifting around on the outer chloroplast membrane can use ATP to add a phosphate group to the Toc34 protein, ... Because it is similar to bacterial amino acid transporters and the mitochondrial import protein Tim17[38] (translocase on the i ... it is known that for about every five Toc75 proteins in the outer chloroplast membrane, there are two Tic20 I proteins (the ... which anchors the protein to the outer chloroplast membrane.[48]. Toc159 probably works a lot like Toc34, recognizing proteins ...
Included are those involved in chemotaxis, outer membrane channel function, degradation of aromatic ring compounds, and the ... "Bacterial Birth Scar Proteins Mark Future Flagellum Assembly Site". Cell. 124 (5): 1025-37. doi:10.1016/j.cell.2006.01.019. ... Cell development involves many such proteins working together. Fig#1 shows how TipN interact with two other polar proteins : ... "A Landmark Protein Essential for Establishing and Perpetuating the Polarity of a Bacterial Cell". Cell. 124 (5): 1011-23. doi: ...
... along with an outer membrane similar to Gram-negative bacteria. Because of their double-membrane envelope, Borrelia bacteria ... Within the tick midgut, the Borrelia's outer surface protein A (OspA) binds to the tick receptor for OspA, known as TROSPA. ... In the US, the National Institutes of Health has supported research into bacterial persistence.[282] ... A recombinant vaccine against Lyme disease, based on the outer surface protein A (ospA) of B. burgdorferi, was developed by ...
Gram-negative bacteria only: Bacterial outer membrane *Porin. *Lipopolysaccharide. *Periplasmic space. *Mycobacteria only: ... Small acid-soluble proteins (SASPs) are found in endospores. These proteins tightly bind and condense the DNA, and are in part ... The plasma membrane of the cell surrounds this wall and pinches off to leave a double membrane around the DNA, and the ... The cortex contains an inner membrane known as the core. The inner membrane that surrounds this core leads to the endospore's ...
Therefore, macrophage membranes become susceptibile to bacterial infections.[11] Reproductive system[edit]. In experiments with ... This process increases transcription of certain genes, notably CYP1A1, followed by increased CYP1A1 protein production.[28] ... because the gastrointestinal tract protects itself against carcinomas by shedding its outer layer continuously.[citation needed ... the molecular mechanism was uncovered as damage to the macrophage membrane's lipid raft integrity by decreasing membrane ...
In oats, β-glucan is found mainly in the endosperm of the oat kernel, especially in the outer layers of that endosperm.[6] ... Mcintosh, M (19 October 2004). "Curdlan and other bacterial (1→3)-β-D-glucans". Applied Microbiology and Biotechnology. 68 (2 ... In addition, these side-chains can be attached to other types of molecules, like proteins, as in polysaccharide-K. ... "Role of the glycocalyx in regulating access of microparticles to apical plasma membranes of intestinal epithelial cells: ...
... which possess a particularly large periplasm that contains membrane-bound vesicles and is enclosed by an outer membrane.[99] ... while archaeal flagella appear to have evolved from bacterial type IV pili.[106] In contrast to the bacterial flagellum, which ... Proteins related to the cytoskeleton components of other organisms exist in archaea,[89] and filaments form within their cells, ... No membrane-bound organelles (questioned[56]) or nucleus. No membrane-bound organelles or nucleus. Membrane-bound organelles ...
1997). ""Comparison of archaeal and bacterial genomes: computer analysis of protein sequences predicts novel functions and ... evidence for a novel outer membrane and for intracellular vesicle budding in an archaeon" (PDF). Archaea 1 (1): 9-18. PMC ... 2002). "Introns in protein-coding genes in Archaea". FEBS Lett. 510 (1-2): 27-30. PMID 11755525. doi:10.1016/S0014-5793(01) ... 1994). "Evolutionary relationships of bacterial and archaeal glutamine synthetase genes". J Mol Evol. (38(6)): 566-576.. ...
The cascade is composed of many plasma proteins, which are made in the liver. The proteins work together to: *trigger the ... To engulf a particle or pathogen, a phagocyte extends portions of its plasma membrane, wrapping the membrane around the ... The outer layers of the skin are called "epithelial". Epithelial cells form a waxy physical barrier that keeps out most ... The binding of bacterial molecules to receptors on the surface of a macrophage triggers it to engulf and destroy the bacteria. ...
The outer two rings each contain seven α subunits whose function is to maintain a "gate" through which proteins enter the ... membrane-bound organelles with acidic and protease-filled interiors that can degrade and then recycle exogenous proteins and ... Some prokaryotes, including many archaea and the bacterial order Actinomycetales, also share homologs of the 20S proteasome, ... The protein degradation processEdit. Ribbon diagram of ubiquitin, the highly conserved protein that serves as a molecular tag ...
... degrades damaged organelles, cell membranes and proteins, and the failure of autophagy is thought to be one of the ... while the LC3 molecules attached to the outer side are cleaved off by Atg4 and recycled.[54] The contents of the autolysosome ... it recruits autophagy adaptor such as NDP52 leading to the formation of an autophagosome and bacterial degradation.[64] ... WIPI2, a PtdIns(3)P binding protein of the WIPI (WD-repeat protein interacting with phosphoinositides) protein family, was ...
However, Shewanella nanowires are not pili, but extensions of the outer membrane that contain the decaheme outer membrane ... "Power generation from ambient humidity using protein nanowires". Nature. 578 (7796): 550-554. doi:10.1038/s41586-020-2010-9. ... Application Significance of Bacterial nanowires[edit]. Bacterial nanowires have been shown to have significant potential ... The reported presence of outer membrane cytochromes, and lack of conductivity in nanowires from the MtrC and OmcA-deficient ...
Lysozyme catalyzes the hydrolysis of the peptidoglycan layer, while EDTA destroys the outer membrane facilitating enzyme's ... Bacterial spheroplasts, with suitable recombinant DNA inserted into it, can be used to transfect animal cells. Spheroplasts ... Yeast cells are normally protected by a thick cell wall which makes extraction of cellular proteins difficult. Enzymatic ... The membrane can then be analyzed on a patch clamp apparatus to determine the phenotype of the ion channels embedded in it. It ...
Additionally, the extracellular matrix and dense outer layer of bacterial cells can protect the inner bacteria cells from ... The antigen (usually a protein or carbohydrate made by an infectious agent) is bound by the antibody, allowing this type of ... and mucous membranes.[21] The portal of entry for a specific microbe is normally dependent on how it travels from its natural ... In 1995 a team at The Institute for Genomic Research sequenced the first bacterial genome; Haemophilus influenzae.[6] A few ...
Underlying the mucous membrane in the mouth is a thin layer of smooth muscle tissue and the loose connection to the membrane ... Saliva also contains a glycoprotein called haptocorrin which is a binding protein to vitamin B12.[17] It binds with the vitamin ... The wall has an outer layer of longitudinal muscles, the taeniae coli, and an inner layer of circular muscles. The circular ... The mucous membrane in the mouth continues as the thin mucosa which lines the bases of the teeth. The main component of mucus ...
For bacterial or viral agents, dose typically refers to the amount of the pathogen required to infect a host. For information ... In trials, early models of the device failed after about half an hour because the proteins in whole blood clung to the sensors ... Whether a drug is ingested orally, injected into a muscle or vein, absorbed through a mucus membrane, or any of the other types ... Subcutaneous injection: the needle is inserted at a 45 degree angle into the (subcutaneous) tissue between the outer layer of ...
The proteins that make up the remaining 20% of the fraction of proteins in cream are known as whey proteins. Whey proteins are ... At a pH of 6.5 the casein micelles repulse each other due to the electronegativity of the outer layer of the micelle.[8] During ... Its name comes from the production of lactic acid by bacterial fermentation, which is called souring. Crème fraîche is one type ... compositions in total fatty acids and in polar lipids from the milk fat globule membrane". Food Chemistry. 120 (2): 544-551. ...
protein phosphatase type 2A complex. • mitochondrion. • mitochondrial inner membrane. • respiratory chain. • nucleus. • ... from the mitochondrial inner membrane and can be extruded into the soluble cytoplasm through pores in the outer membrane.[21] ... A bacterial cytochrome c functions as a nitrite reductase.[19]. Role in apoptosis[edit]. Cytochrome c also has an intermediate ... UMich Orientation of Proteins in Membranes families/superfamily-78 - Calculated orientations of cytochromes c in the lipid ...
Secondary bacterial infection of the skin is a relatively uncommon complication of smallpox. When this occurs, the fever ... By days 12-15, the first visible lesions - small reddish spots called enanthem - appeared on mucous membranes of the mouth, ... Sometimes, the blisters merged into sheets, forming a confluent rash, which began to detach the outer layers of skin from the ... In order to replicate, poxviruses produce a variety of specialized proteins not produced by other DNA viruses, the most ...
Bacterial or viral[edit]. As bacterial and viral infections can both cause the same kinds of symptoms, it can be difficult to ... Outer space[edit]. Main articles: Effect of spaceflight on the human body, Medical treatment during spaceflight, and Space ... The ability of the viral protein hemagglutinin to bind red blood cells together into a detectable matrix may also be ... this virus must spread through skin lesions or permeable membranes such as the eye. Thus, the initial stage of Ebola is not ...
This membrane is composed of a phospholipid inner membrane, a phospholipid outer membrane, and an intermembrane space. Enclosed ... Embedded in the thylakoid membrane are integral and peripheral membrane protein complexes of the photosynthetic system. ... "Atomic-level structural and functional model of a bacterial photosynthetic membrane vesicle". Proceedings of the National ... In photosynthetic bacteria, the proteins that gather light for photosynthesis are embedded in cell membranes. In its simplest ...
Pavkov-Keller T, Howorka S, Keller W (2011). The structure of bacterial S-layer proteins. Prog. Molec. Biol. Transl. Sci. ... In Gram-negative bacteria (e) the S-layer is closely associated with the lipopolysaccharide of the outer membrane. Figure and ... Thus, the S-layer protein can represent up to 15% of the whole protein content of a cell.[3] S-layer proteins are poorly ... of the Methanosarcinales S-layer Tile Protein family and a bacterial S-layer protein (SbsB), from Geobacillus ...
General avian tympanic membrane form is ovular and slightly conical. Morphological differences in the middle ear are observed ... Syndactyly, as it occurs in birds, is like anisodactyly, except that the third and fourth toes (the outer and middle forward- ... which are amino acid chains that are shorter than the original dietary protein.[42][43] The gastric juices (hydrochloric acid ... which breaks down certain specific peptide bonds found in proteins, to produce a set of peptides, ...
Gram-negative bacteria only: Bacterial outer membrane *Porin. *Lipopolysaccharide. *Periplasmic space. *Mycobacteria only: ... Penicillin binding protein forming cross-links in newly formed bacterial cell wall. ... Stage two occurs in the cytoplasmic membrane. It is in the membrane where a lipid carrier called bactoprenol carries ... Penicillin-binding proteins form the bonds between oligopeptide crosslinks in peptidoglycan. For a bacterial cell to reproduce ...
Gram-negative bacteria only: Bacterial outer membrane *Porin. *Lipopolysaccharide. *Periplasmic space. *Mycobacteria only: ... Proteins are shown in blue and the single RNA strand in tan.[13] ... List of bacterial orders. *List of sequenced bacterial genomes ... a b Bacterial phyla entry in LPSN [. Euzéby, J.P. (1997). "List of Bacterial Names with Standing in Nomenclature: a folder ... Branching order of bacterial phyla (Rappe and Giovanoni, 2004). *Branching order of bacterial phyla after ARB Silva Living Tree ...
No, except that Homoscleromorpha have basement membranes.[24]. Yes: inter-cell connections; basement membranes. ... 1: Gap 2: Central cavity 3 Internal wall 4: Pore (all walls have pores) 5 Septum 6 Outer wall 7 Holdfast ... Members of this family have been found to have anti-cancer, anti-bacterial and anti-fungal properties. One example isolated ... A very large and internally consistent alignment of 1,719 proteins at the metazoan scale, published in 2017, showed that (i) ...
Fitting Periplasmic Membrane Fusion Proteins to Inner Membrane Transporters: Mutations That Enable Escherichia coli AcrA To ... Compromised Outer Membrane Integrity in Vibrio cholerae Type II Secretion Mutants Aleksandra E. Sikora, Suzanne R. Lybarger, ... Outer Membrane Components of the Tad (Tight Adherence) Secreton of Aggregatibacter actinomycetemcomitans Sarah A. Clock, Paul J ... A TolC-Like Protein Is Required for Heterocyst Development in Anabaena sp. Strain PCC 7120 Suncana Moslavac, Kerstin Nicolaisen ...
Intrinsically disordered protein threads through the bacterial outer-membrane porin OmpF.. Housden NG1, Hopper JT, Lukoyanova N ... Intrinsically Disordered Protein Threads through the Bacterial Outer Membrane Porin OmpF. Science. ;340(6140):10.1126/science. ... Intrinsically Disordered Protein Threads through the Bacterial Outer Membrane Porin OmpF. Science. ;340(6140):10.1126/science. ... Intrinsically Disordered Protein Threads through the Bacterial Outer Membrane Porin OmpF. Science. ;340(6140):10.1126/science. ...
Inflammasome Activation by Bacterial Outer Membrane Vesicles Requires Guanylate Binding Proteins. Ryan Finethy, Sarah Luoma, ... Inflammasome Activation by Bacterial Outer Membrane Vesicles Requires Guanylate Binding Proteins. Ryan Finethy, Sarah Luoma, ... Inflammasome Activation by Bacterial Outer Membrane Vesicles Requires Guanylate Binding Proteins. Ryan Finethy, Sarah Luoma, ... Inflammasome Activation by Bacterial Outer Membrane Vesicles Requires Guanylate Binding Proteins Message Subject (Your Name) ...
This protein is a porin found in the outer membranes of gram-negative bacteria like E. coli. Porins are beta barrel proteins ... Computer model showing a part of the secondary structure of a molecule of outer membrane protein A from Escherichia coli (E. ... that cross a cellular membrane and act as a pore through which molecules can diffuse - Stock Image C014/7655 ... Bacterial outer membrane protein molecule. Computer model showing a part of the secondary structure of a molecule of outer ...
Computer model showing a part of the secondary structure of a molecule of outer membrane protein A from Escherichia coli (E. ... Bacterial outer membrane protein molecule. Computer model showing a part of the secondary structure of a molecule of outer ... This protein is a porin found in the outer membranes of gram-negative bacteria like E. coli. Porins are beta barrel proteins ... membrane protein A from Escherichia coli (E. coli) bacteria. ... Bacterial outer membrane protein molecule. C014/7656. Rights ...
Proteins forming large channels from bacterial and mitochondrial outer membranes: porins and phage lambda receptor protein.. ...
... bacterial membrane proteins in 12% T pristine PAM (left) and 12% T Graphene/PAM (right); (c) Bacterial membrane proteins in 15 ... Outer membrane protein-A OmpA, a bacterial recombinant from Prospec Protein Specialists, Israel, Bisacrylamide (N,N -methylene ... Lotus-leaf Inspired Hydrophobic Nanocomposite Matrices for Electrophoretic Separation of Bacterial Outer Membrane Proteins. ... Lotus-leaf Inspired Hydrophobic Nanocomposite Matrices for Electrophoretic Separation of Bacterial Outer Membrane Proteins. ...
Interaction between bacterial outer membrane proteins and periplasmic quality control factors: a kinetic partitioning mechanism ... Interaction between bacterial outer membrane proteins and periplasmic quality control factors: a kinetic partitioning mechanism ... Interaction between bacterial outer membrane proteins and periplasmic quality control factors: a kinetic partitioning mechanism ... Interaction between bacterial outer membrane proteins and periplasmic quality control factors: a kinetic partitioning mechanism ...
A record-breaking beta barrel allows protein transport across the bacterial outer membrane, Representing biochemistry research ... Bacterial outer membrane proteins have a distinctive beta barrel architecture in which a sheet of polypeptide strands forms a ... export these proteins across two cell membranes. Protein transport across the outer membrane in these bacteria utilises the ... A record-breaking beta barrel allows protein transport across the bacterial outer membrane ...
2003) Role of a highly conserved bacterial protein in outer membrane protein assembly. Science 299:262-265.. ... 2000) Structure and function of bacterial outer membrane proteins: Barrels in a nutshell. Mol Microbiol 37:239-253.. ... the inner and outer membranes. The inner membrane (IM), which surrounds the cytoplasm, is separated from the outer membrane (OM ... 2004) Identification of an outer membrane protein required for the transport of lipopolysaccharide to the bacterial cell ...
... they utilize an inner membrane protein, TonB, that couples across the periplasm to an outer membrane transporter for import of ... Outer Membrane Proteins. Schematic differences between Gram-positive (left) and Gram-negative (right) bacteria. The former have ... The outer membrane of Gram-negative bacteria (those possessing two enveloping membranes with a periplasm in between, as seen ... C) a model outer membrane with LPS in the outer (top) and phospholipids within the inner (bottom) leaflets . ...
... across bacterial phyla but multi MCE domain-containing proteins evolved in Proteobacteria from single-domain proteins. Mutants ... protein MlaD is known to be part of an inner membrane transporter that is important for maintenance of outer membrane lipid ... the latter of which is an orthologue of MAM-7 that was previously reported to be an outer membrane protein. We show that all ... three MCE domain-containing proteins localise to the inner membrane. Bioinformatic analyses revealed that MCE domains are ...
... were chosen for proteomic analysis of their outer membrane proteins (OMPs). 1D gel analysis revealed a ~29 kDa size band that ... These were the flagellar hook protein FlgE, flagellar hook-associated protein 1, flagellar hook-associated protein, flage... ... These were the flagellar hook protein FlgE, flagellar hook-associated protein 1, flagellar hook-associated protein, flagellin ... The presence of flagellin protein was confirmed in 2D gel spot. Mass spectrometry analysis of total OMPs revealed that the four ...
Handover mechanism of the growing pilus by the bacterial outer-membrane usher FimD. ... Handover mechanism of the growing pilus by the bacterial outer-membrane usher FimD. Du M, Yuan Z, Yu H, Henderson N, Sarowar S ... Outer membrane usher protein FimD. > Outer membrane usher protein * Occurring in:. *Outer membrane usher protein FimD. > ... Chaperone protein FimC. > Pili assembly chaperone, bacterial * Occurring in:. *Protein FimF. *Protein FimG. *Type 1 fimbrin D- ...
... is recognized by the noncanonical inflammasome protein caspase-11 in the cytosol of infected host cells and thereby prompts an ... The Gram-negative bacterial cell wall component lipopolysaccharide (LPS) ... Inflammasome activation by bacterial outer membrane vesicles requires guanylate binding proteins. *Finethy R ... Inflammasome activation by bacterial outer membrane vesicles requires guanylate binding proteins. MBio, 8(5). ...
Ion channels and bacterial outer membrane proteins",. keywords = "Anisotropy, Bacterial Outer Membrane Proteins, Bacterial ... Membrane protein simulations: Ion channels and bacterial outer membrane proteins. Advances in Protein Chemistry. 2003;66:159- ... Anisotropy, Bacterial Outer Membrane Proteins, Bacterial Proteins, Cell Membrane, Computer Simulation, Ions, Lipid Bilayers, ... KW - Anisotropy, Bacterial Outer Membrane Proteins, Bacterial Proteins, Cell Membrane, Computer Simulation, Ions, Lipid ...
The simulations help to explain the mechanism of formation of low conductance pores within the outer membrane. ... Lipid-protein interactions within the simulations were analyzed and revealed that aromatic side-chains (Trp, Tyr) of OprF ... The N-terminal domains of both proteins have been demonstrated to form low conductance channels in lipid bilayers. Homology ... OprF is a major outer membrane protein from Pseudomonas aeruginosa, a homolog of OmpA from Escherichia coli. ...
Reconstitution of a nanomachine driving the assembly of proteins into bacterial outer membranes. / Shen, Hsin-Hui; Leyton, ... Reconstitution of a nanomachine driving the assembly of proteins into bacterial outer membranes. In: Nature Communications. ... Reconstitution of a nanomachine driving the assembly of proteins into bacterial outer membranes. Nature Communications. 2014;5( ... title = "Reconstitution of a nanomachine driving the assembly of proteins into bacterial outer membranes", ...
Simulations contribute to study on critical bacterial outer membrane protein Share Share Share ...
Anti-Bacterial Agents / pharmacology* * Bacterial Outer Membrane Proteins / immunology * Bacterial Outer Membrane Proteins / ... For this purpose, the presence of OprD protein in the cell wall was detected by Western blot and beta-lactamase activity by ...
Genes encoding the type III secretion machinery, its substrates, and several regulatory proteins all reside on a 70-Kb ... which is required for the delivery of effector Yop proteins into target cells during infection. ... Bacterial Outer Membrane Proteins / genetics* * Bacterial Outer Membrane Proteins / physiology* * Chromosomes, Bacterial / ... Pathogenic Yersinia species possess a type III secretion system, which is required for the delivery of effector Yop proteins ...
We identified new class-II epitopes within Salmonella type-III secretion system effector proteins and generated a methodology ... Author Summary Pathogens alter protein expression in an infected host, depending on metabolic or virulence requirements, but ... Outer membrane proteins Is the Subject Area "Outer membrane proteins" applicable to this article? Yes. No. ...
Changes in membrane permeability, including decreased influx and/or increased efflux of antibiotics, are known as key ... contributors of bacterial MDR. Therefore, it is of critical importance to understand molecular mechanisms that link membrane ... This report provides a comprehensive analysis of membrane alterations relative to mutational steps in the evolution of MDR of a ... Transport assays were used to characterize membrane permeability defects. Simultaneous genome-wide analysis allowed the ...
Dispensable loops shield the functionally-important extracellular loops of the essential Gram-negative bacterial outer membrane ... The structure of bacterial outer membrane proteins * GE Schulz. (2002) Biochimica et Biophysica Acta (BBA) - Biomembranes 1565: ... The complex that inserts lipopolysaccharide into the bacterial outer membrane forms a two-protein plug-and-barrel * E Freinkman ... Identification of two inner-membrane proteins required for the transport of lipopolysaccharide to the outer membrane of ...
Contamination with bacterial outer membrane proteins. J Biol Chem. 2004;279:23661-7. DOIPubMed ... Prion diseases are neurodegenerative conditions associated with a misfolded and infectious protein, scrapie prion protein (PrP ... Dagdanova A, Ilchenko S, Notari S, Yang Q, Obrenovich ME, Hatcher K, Characterization of the prion protein in human urine. J ... Van Dorsselaer A, Carapito C, Delalande F, Schaeffer-Reiss C, Thierse D, Diemer H, Detection of prion protein in urine-derived ...
We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their ... InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites ... structure found in the C-terminal region of many Gram-negative bacterial outer membrane proteins [PMID: 1538702], such as porin ... Outer membrane protein A of Escherichia coli K1 selectively enhances the expression of intercellular adhesion molecule-1 in ...
Formation of a gated channel by a ligand-specific transport protein in the bacterial outer membrane. Science 258:471-475. ... ENZYMES AND PROTEINS. Insight from TonB Hybrid Proteins into the Mechanism of Iron Transport through the Outer Membrane. ... Outer membrane proteins of Escherichia coli. I. Effect of preparative conditions on the migration of protein in polyacrylamide ... TonB protein appears to transduce energy by shuttling between the cytoplasmic membrane and the outer membrane in Escherichia ...
Here, we offer a rationale for charged S-layer proteins in the context of the structural evolution of S-layers. Using the ... Despite exceptional sequence diversity, S-layer proteins (SLPs) share important characteristics such as their ability to form ... Nikaido H, Vaara M. Molecular basis of bacterial outer membrane permeability. Microbiol Rev. 1985;49:1-32. ... e Molecular organization of S-layer proteins and AMO. S-layer proteins are anchored in the membrane at the N-terminus, forming ...
... major outer membrane protein haemagglutinin (HA) with Vm-HA/Protease: Implication for understanding bacterial adherence. ... major outer membrane protein haemagglutinin (HA) with Vm-HA/Protease : Implication for understanding bacterial adherence. In: ... major outer membrane protein haemagglutinin (HA) with Vm-HA/Protease: Implication for understanding bacterial adherence. ... major outer membrane protein haemagglutinin (HA) with Vm-HA/Protease: Implication for understanding bacterial adherence, ...
... plays an integral function in the positioning and folding of other outer membrane proteins into the bacterial outer membrane. ... Omp85is a highly conserved outer membrane protein found in all gram-negative bacteria. It is essential for bacterial cell ... Evidence of Positive Darwinian Selection in Omp85, a Highly Conserved Bacterial Outer Membrane Protein Essential for Cell ... a Highly Conserved Bacterial Outer Membrane Protein Essential for Cell Viability. Journal of Molecular Evolution, 61 (1). pp. ...
  • Computer model showing a part of the secondary structure of a molecule of outer membrane protein A from Escherichia coli (E. coli) bacteria. (
  • This protein is a porin found in the outer membranes of gram-negative bacteria like E. coli. (
  • LPS can be released from lysed bacteria as "free" LPS aggregates or actively secreted by live bacteria as a component of outer membrane vesicles (OMVs). (
  • IMPORTANCE The bacterial cell wall component LPS is a strong inducer of inflammation and is responsible for much of the toxicity of Gram-negative bacteria. (
  • Bacteria shed some of their cell wall and its associated LPS in the form of outer membrane vesicles (OMVs). (
  • The OMPs (outer membrane proteins) of Gram-negative bacteria have to be translocated through the periplasmic space before reaching their final destination. (
  • New research from the Berks (Biochemistry) and Lea (Pathology) groups reveals how proteins are transported across the outer membrane of bacteria responsible for severe dental disease (peridontitis). (
  • Pathogenic bacteria must be able to secrete proteins in order to manipulatetheir host organism. (
  • Protein transport across the outer membrane in these bacteria utilises the recently discovered Type IX Secretion System (T9SS). (
  • The outer membrane (OM) of most Gram-negative bacteria contains lipopolysaccharide (LPS) in the outer leaflet. (
  • The hallmark of Gram-negative bacteria is the presence of two extracytoplasmic membranes: the inner and outer membranes. (
  • The outer membrane of Gram-negative bacteria (those possessing two enveloping membranes with a periplasm in between, as seen above right) is unique for a number of a reasons. (
  • Nonetheless, bacteria often need to actively import large and/or scarce nutrients across the outer membrane. (
  • Just as bacteria need to import molecules across the outer membrane, they sometimes need to export them as well. (
  • The outer membrane of Gram-negative bacteria is asymmetric, with lipopolysaccharides (LPS) and phospholipids found in the outer and inner leaflets, respectively. (
  • Outer membrane proteins (OMPs) in Gram-negative bacteria dictate permeability of metabolites, antibiotics, and toxins. (
  • Gram-negative bacteria are wrapped in an outer membrane made of large molecules called lipopolysaccharides. (
  • The outer membrane (OM) of Gram-negative bacteria is a permeability barrier to antibiotics and other cytotoxic agents, such as detergents ( Nikaido, 2003 ). (
  • Omp85is a highly conserved outer membrane protein found in all gram-negative bacteria. (
  • used the new method to make predictions about the protein-protein interfaces in 28 protein complexes found in bacteria, and also to make a prediction about the interface between protein subunits in the bacterial ribosome. (
  • The next challenge is to extend the method to protein complexes that are found only in eukaryotes (i.e., not in bacteria). (
  • Gram-negative bacteria naturally produce and secrete nanosized outer membrane vesicles (OMVs). (
  • To test this we engineered the Gram-negative bacterium Bacteroides thetaiotaomicron (Bt), a prominent member of the intestinal microbiota of all animals, to incorporate bacteria-, virus- and human-derived proteins into its OMVs. (
  • Bacterial Outer Membrane Proteins (OMPs) play an important role in infectious process of many bacteria. (
  • Mice that received the encapsulated Schu S4 membranes followed by a booster of LVS bacteria showed significant protection with respect to a lethal Schu S4 challenge compared to control mice. (
  • The mechanism of membrane insertion and assembly of b-barrel proteins is a central question of outer membrane biogenesis of mitochondria, chloroplasts, and Gram-negative bacteria. (
  • Although outer membrane impermeability was originally proposed to be responsible for broad-spectrum intrinsic resistance in gram-negative bacteria, it is now well understood that it must be coupled to a secondary mechanism such as active drug efflux ( 15 ). (
  • The multidrug resistance (MDR) efflux systems of gram-negative bacteria have a three-component structure that allows the expulsion of compounds through two membranes. (
  • beta barrel proteins, which are found only in outer membranes of Gram-negative bacteria , and outer membranes of mitochondria and chloroplasts . (
  • Concise chapters, written by experts in the field, cover a wide spectrum of topics on lipid and membrane formation in microbes (Archaea, Bacteria, eukaryotic microbes). (
  • Functional Roles of Individual Membrane Lipids in Bacteria, Archaea and Eukaryotic Microbes. (
  • Outer Membrane Extension Nanowires of Bacteria. (
  • Outer Membrane Vesicles of Bacteria. (
  • Regulation of Membrane Lipid Homeostasis in Bacteria upon Temperature Change. (
  • Descubrimos que algunas enzimas del metabolismo de flavinas constituyen factores de virulencia que actúan en el nicho replicativo de la bacteria, y que Brucella tiene un metabolismo de síntesis de flavinas atípico. (
  • Antibiotics modulate a wide range of biological processes in bacteria and as such, the study of bacterial cellular signaling could aid the development of urgently needed new antibiotic agents. (
  • Bacteria are capable of modifying serine/threonine/tyrosine residues on proteins like eukaryotes, but in addition use two-component signaling that relies on histidine autophosphorylation of sensory kinases as the first component and aspartate phosphorylation of response regulators as the second component ( 12 ). (
  • It is a common pathway amongst Gram-negative bacteria for secreting toxic and flagellar proteins. (
  • The bacterial outer membrane (OM) is a peculiar biological structure with a unique composition that contributes significantly to the fitness of Gram-negative bacteria in hostile environments. (
  • Many Bacteria are surrounded by an additional lipid bilayer, the outer membrane (OM), and are, thus, described as diderm bacteria. (
  • The OM is not present in monoderm bacteria, which possess the cytoplasmic membrane as the unique lipid membrane [ 4 , 5 , 6 ]. (
  • The chaperone machinery that facilitates outer membrane protein biogenesis in bacteria is most fascinating, both from the view of fundamental biophysics, as well as from the perspective of microbiology. (
  • We discovered a novel protein transport system, the TAM, found in most sequenced gram-negative bacteria that's required for autotransporter biogenesis. (
  • Bacteria have mechanisms to export proteins for diverse purposes, including colonization of hosts and pathogenesis. (
  • A small number of archetypal bacterial secretion machines have been found in several groups of bacteria and mediate a fundamentally distinct secretion process. (
  • A paper in Molecular & Cellular Proteomics investigated how N. meningitidis and other Gram-negative bacteria transport these proteins. (
  • DiRienzo JM, Nakamura K, Inouye M. The outer membrane proteins of Gram-negative bacteria: biosynthesis, assembly, and functions. (
  • OMP porins are present in the outer membranes of Gram-negative bacteria, mitochondria and plastids. (
  • 1000 Da) molecules across the outer membranes of bacteria and organelles with variable degrees of selectivity. (
  • All Gram-negative bacteria are enclosed by an outer membrane which acts as an additional protection barrier preventing the entry of toxic compounds including antibiotics and antimicrobial peptides (AMPs). (
  • Porins are β-barrel outer-membrane proteins through which small solutes and metabolites diffuse that are also exploited during cell death. (
  • Porins are beta barrel proteins that cross a cellular membrane and act as a pore through which molecules can diffuse. (
  • Proteins forming large channels from bacterial and mitochondrial outer membranes: porins and phage lambda receptor protein. (
  • Another unique aspect of the outer membrane is that it's full of porins, which permit the diffusion of small molecules relatively easily across it. (
  • However, ferric siderophores, like ferric enterobactin (FeEnt), are too large (716 Da) to pass through general porins in the outer membrane (OM), necessitating a different type of transporter to acquire them. (
  • MAPF Perl5 program for predicting transmembrane beta strands in outer membrane porins from input multiple alignments in MSF format. (
  • This two-component system controls the expression of several products, including the outer membrane porins OmpC and OmpF, in response to changes in osmolarity. (
  • In addition, the OM contains lipoproteins and integral outer membrane proteins (OMPs), most of which span the OM via antiparallel β-sheets that fold into β-barrels ( 4 , 6 ). (
  • In this study, eight strains of C. malonaticus ST7, that had been isolated from a wide range of sources and varied in their in vitro virulence, were chosen for proteomic analysis of their outer membrane proteins (OMPs). (
  • Mass spectrometry analysis of total OMPs revealed that the four highly invasive C. malonaticus strains expressed the main flagellum proteins that were absent from the four low invasive strains. (
  • Elucidating the structure-function relationships governing OMPs within native membrane environments remains challenging. (
  • Immunoblotting identified 32, 37, 72 and 89 kDa protein bands as immunogenic OMPs. (
  • The Outer Membrane Proteins (OMPs) of the isolates were extracted as per the method described by Davies (1991) . (
  • OM proteins (OMPs) and lipoproteins are also embedded and anchored, respectively, in the OM [ 7 ]. (
  • While the process is catalyzed in vivo by an assembly line of more than eight chaperones, most β-barrel outer membrane proteins (Omps) can also autonomously fold and insert into a target membrane or membrane mimic. (
  • Sinisa Vidovic and his team are working to develop a live, attenuated vaccine against critical outer membrane proteins (OMPs), which can prevent Salmonella colonization of chickens and turkeys. (
  • In addition, we examined 10 60-KDa, outer-membrane protein-2 genes, all but one of which were from these same strains. (
  • The tree was not, among the trachomatis strains, congruent with the major-outer-membrane protein tree, suggesting that gene exchange could be occurring among strains. (
  • Spectral counting of mass spectrometric data showed enrichment for membrane proteins in both strains. (
  • Bacterial strains living in the environment must cope with the toxic compounds originating from humans production. (
  • The evolutionary changes in the outer membrane proteins have led to the emergence of new strains which can infect a larger variety of hosts. (
  • Both strains showed a porin pattern different from that of a susceptible strain, with a drastic reduction in the amount of the major porin but with an apparently conserved normal structure (size and immunogenicity), together with overproduction of two known outer membrane proteins, OmpX and LamB. (
  • Bacterial strains, growth conditions, and antibiotic susceptibility tests. (
  • The appearance of alternate colony shapes on LB agar was used to track mutant bacterial strains. (
  • Strains present as less than 1% of the total bacterial CFU were not detectable. (
  • Samples of a continuous culture of E. coli O157:H7 and bacteriophage PP01 were taken at the indicated times, and the supernatants were stored and used for plaque assay on the mutant bacterial strains also isolated from the continuous culture. (
  • compare the effects of acute dietary deficiency of vitamin A, folate, iron, or zinc in gnotobiotic mice harboring bacterial strains common in the human gut. (
  • Intrinsically disordered protein threads through the bacterial outer-membrane porin OmpF. (
  • Thus, an intrinsically disordered protein can tunnel through the narrow pores of an oligomeric porin to deliver an epitope signal to the cell to initiate cell death. (
  • SDS-PAGE in the nanocomposite matrices of a commercial outer membrane porin protein, OmpA indicated a significant decrease in anomalous migration of the protein with increasing carbon nanotube loading in the gel matrix. (
  • Porin proteins in the OM control permeability to hydrophilic molecules, but unlike typical phospholipid bilayers, the OM is quite impermeable to hydrophobic molecules, mainly because of LPS ( 1 ). (
  • Outer membrane porin F (gene oprF) from Pseudomonas. (
  • The monomeric porin OmpG is especially attractive compared with multisubunit proteins because appropriate modifications of the pore can be easily achieved by mutagenesis. (
  • The mitochondrial outer membrane plays a crucial role in the biogenesis, inheritance and dynamics of the organelle and forms the functional and signaling link between mitochondria and the rest of the eukaryotic cell. (
  • Membrane Lipid Biogenesis. (
  • Molecular chaperones play a key role in cellular processes, including protein homeostasis, but also in membrane protein transport and biogenesis. (
  • Disulfide transfer pathways that function in the endoplasmic reticulum (ER) and chloroplasts of plants play critical roles in the development of protein storage organelles and the biogenesis of chloroplasts, respectively. (
  • The IM is composed of phospholipids, integral transmembrane (TM) proteins that span the IM with α-helical TM domains, and lipoproteins ( 3 , 4 ). (
  • OM lipoproteins interact with the ABC transporter LolCDE, which extracts them from the IM and passes these proteins to the periplasmic chaperone LolA for delivery to LolB at the OM ( 4 ). (
  • To determine whether or not LolA is generally involved in the outer membrane localization of lipoproteins in vivo, the chromosomal lolA gene was manipulated so as to be controlled by the lac promoter-operator. (
  • Although LolA depletion did not immediately arrest the growth of cells lacking Lpp, disruption of the chromosomal lolA gene was lethal to the lpp strain, indicating that LolA is generally required for the outer membrane localization of lipoproteins, and therefore essential irrespective of the presence or absence of Lpp. (
  • Toll-like receptor (TLR) 4 has been identified as the primary receptor for enteric LPS, whereas TLR2 has been implicated as the receptor for Gram-positive and fungal cell wall components and for bacterial, mycobacterial, and spirochetal lipoproteins. (
  • Vertebrates and invertebrates initiate a series of defense mechanisms in response to infection by various microorganisms by sensing the presence of conserved pathogen-associated molecular patterns, such as bacterial LPS or lipoproteins ( 5 , 13 ). (
  • Trafficking of N. meningitidis lipoproteins to the outer bacterial membrane determines which antigens are available for immune recognition. (
  • The aqueous environment of the periplasmic space and high permeability of the outer membrane engender such a translocation process inevitably challenging. (
  • The periplasmic end of the SprA barrel is open in the PorV complex but is occluded by the Plug protein in the Plug complex. (
  • Before LPS is assembled at the OM, it must be synthesized at the inner membrane (IM) and transported across the aqueous periplasmic compartment. (
  • The major outer membrane lipoprotein (Lpp) of Escherichia coli is released from the cytoplasmic membrane into the periplasm as a complex with LolA, a periplasmic chaperone, prior to the localization in the outer membrane. (
  • We use this method to make subunit contact predictions for an additional 36 protein complexes with unknown structures, and present models based on these predictions for the tripartite ATP-independent periplasmic (TRAP) transporter, the tripartite efflux system, the pyruvate formate lyase-activating enzyme complex, and the methionine ABC transporter. (
  • FUNCTION: Translocates 4-amino-4-deoxy-L-arabinose- CC phosphoundecaprenol (alpha-L-Ara4N-phosphoundecaprenol) from the CC cytoplasmic to the periplasmic side of the inner membrane (By CC similarity). (
  • MexB), (ii) a trimeric channel-forming outer membrane pore component that spans both the outer membrane and periplasm (OprM), and (iii) a membrane-anchored periplasmic linker protein (MexA) that is thought to promote interaction between the RND pump and the outer membrane efflux channel (17, 24 ). (
  • The signal peptide, cleaved at the inner membrane, guides the autotransporter protein to the periplasmic space. (
  • This mechanism translocates proteins lacking an N-terminal signal peptide across the cell membrane in one step, as it does not require an intermediate periplasmic process to cleave the signal peptide. (
  • LbtU is an outer membrane protein consisting of a 16-stranded transmembrane β-barrel, multiple extracellular domains, and short periplasmic tails. (
  • All protein transport systems have to provide an aqueous pathway across the otherwise hydrophobic membrane bilayer. (
  • However, for the T9SS it was unknown which proteins build this protein conducting pathway, or translocon. (
  • In particular, we see in multiple contexts that the interior domain of the transporter unfolds, generating a pathway for the substrate across the membrane. (
  • In E. coli , this Mla pathway has been shown to play a role in outer membrane maintenance through trafficking of phospholipids from the cell surface back into the cell 14 . (
  • The Mla pathway in E. coli is important for maintaining this lipid asymmetry as mutations in the pathway, including MlaD, result in phospholipid accumulation in the outer leaflet of the outer membrane 14 . (
  • This OMV-mediated pathway for host-microbe interactions could be exploited to deliver biologically active proteins to the body. (
  • They systematically mapped precursor proteins transported by the mitochondrial Omp85 channel (Sam50) to elucidate the entire membrane insertion pathway of a precursor in the native membrane environment. (
  • In molecular biology, the FHIPEP protein family (Flagellar/Hr/Invasion Proteins Export Pore family)consists of a number of proteins that constitute the type III secretion (or signal peptide-independent) pathway apparatus. (
  • The pathway apparatus comprises three components: two within the inner membrane and one within the outer. (
  • The endoplasmic reticulum (ER) is the first organelle in the secretory pathway, and this dynamic and highly specialized organelle contains enzymes and chaperones that mediate the folding and assembly of newly synthesized proteins [ 1 ]. (
  • Extracellular and endocytosed LPS is recognized by the transmembrane protein Toll-like receptor 4 (TLR4) and prompts discrete signaling events originating from the plasma membrane and from endosomes ( 2 , 3 ). (
  • This work, which is published in Nature [1,2], has uncovered an enormous transmembrane beta barrel structure through which the proteins move. (
  • We propose that these two proteins, which we have renamed LptF and LptG, respectively, are the missing transmembrane components of the ABC transporter that, together with LptB, functions to extract LPS from the IM en route to the OM. (
  • The N-terminal half is variable although some of the proteins in this group have the OmpA-like transmembrane domain IPR000498 at the N terminus. (
  • [1] [2] The integral membrane proteins are classified as transmembrane proteins that span across the membrane and integral monotopic proteins that are attached to only one side of the membrane. (
  • Schematic representation of transmembrane proteins: 1. (
  • a single transmembrane α-helix ( bitopic membrane protein ) 2. (
  • a polytopic transmembrane α-helical protein 3. (
  • Integral polytopic proteins are transmembrane proteins that span across the membrane more than once. (
  • These proteins may have different transmembrane topology . (
  • Bitopic proteins are transmembrane proteins that span across the membrane only once. (
  • Transmembrane helices from these proteins have significantly different amino acid distributions to transmembrane helices from polytopic proteins. (
  • Structure:Function of Transmembrane Domains of Proteins and Transmembrane Organelles. (
  • TLR family members are type I transmembrane proteins with leucine-rich repeat extracellular domains and conserved cytoplasmic domains with homology to the mammalian IL-1R ( 27 , 28 ). (
  • Within the sequence, the N terminus is highly conserved and hydrophobic, suggesting that this terminus is embedded within the membrane, with 6-8 transmembrane (TM) domains, while the C terminus is less conserved and appears to be devoid of TM regions. (
  • however, we provide strong evidence that X. fastidiosa secretes wild-type XfYgiT into the extracellular environment via outer membrane vesicles, as confirmed by Western blotting and specific immunofluorescence labeling visualized by fluorescence microscopy. (
  • Membrane Vesicles, Nanopods and Nanotubes of Archaea. (
  • Outer membrane proteins of Escherichia coli , were isolated and characterized by Fourier Transform Infrared Spectroscopy. (
  • When the nanocomposite gels were tested for electrophoretic separation of outer membrane proteins isolated from E. coli, the resolution of protein bands improved with respect to the pristine polyacrylamide gel. (
  • Especially, graphene/polyacrylamide composite hydrogels yielded far better resolution and faster migration of the E. coli membrane proteins compared to multi-walled carbon nanotube/polyacrylamide composite hydrogels. (
  • The species specific structural gene for the monomeric form of A-protein was cloned into a pET-3d plasmid in order to express and produce a recombinant form of the protein in E. coli BL21 (DE3). (
  • This led to the discovery of two essential Escherichia coli IM proteins of unknown function, YjgP and YjgQ, which are required for the transport of LPS to the cell surface. (
  • In Escherichia coli , the single-domain protein MlaD is known to be part of an inner membrane transporter that is important for maintenance of outer membrane lipid asymmetry. (
  • Here we describe two multi MCE domain-containing proteins in Escherichia coli , PqiB and YebT, the latter of which is an orthologue of MAM-7 that was previously reported to be an outer membrane protein. (
  • Two other proteins in E. coli , PqiB and YebT, are predicted to contain MCE domains 21 . (
  • Given the wide distribution of MCE domains across Proteobacteria, we sought to understand functional and evolutionary relationships between these proteins, with a particular focus on those found in E. coli . (
  • OprF is a major outer membrane protein from Pseudomonas aeruginosa, a homolog of OmpA from Escherichia coli. (
  • 3000 monoclonal antibodies to assess the roles of extracellular loops (ECLs) in LptD, an essential OMP that inserts lipopolysaccharide into the outer membrane of Escherichia coli . (
  • MotB (and MotA) serves two functions in E. coli, the MotA(4)-MotB(2) complex attaches to the cell wall via MotB to form the stator of the flagellar motor, and the MotA-MotB complex couples the flow of ions across the cell membrane to movement of the rotor [ PMID: 17052729 ]. (
  • Export and sorting of the Escherichia coli outer membrane protein OmpA. (
  • Outer membrane protein A of Escherichia coli K1 selectively enhances the expression of intercellular adhesion molecule-1 in brain microvascular endothelial cells. (
  • Finally, sequence analyses revealed homology in the TonB C terminus to E. coli YcfS, a proline-rich protein that contains the lysin (LysM) peptidoglycan-binding motif. (
  • The outer membrane protein FadL (product of the fadL gene) of Escherichia coli is required for the specific binding and transport of exogenous long- chain fatty acids prior to metabolic utilization. (
  • These proteins display a high similarity to their homologs in X. fastidiosa strain Temecula and a predicted tridimensional structure that is similar to MqsR-YgiT from Escherichia coli . (
  • Sugar permeation through maltoporin of Escherichia coli, a trimer protein that facilitates maltodextrin translocation across outer bacterial membranes, was investigated at the single channel level. (
  • Nascent Lep inserts into the Escherichia coli inner membrane in the vicinity of YidC, SecY and SecA. (
  • Functional analysis of the TAM in Citrobacter rodentium , Salmonella enterica and Escherichia coli showed that it consists of an Omp85-family protein, TamA, in the outer membrane and TamB in the inner membrane of diverse bacterial species. (
  • Numerous sRNAs have been identified using both computational analysis and laboratory-based techniques such as Northern blotting, microarrays and RNA-Seq in a number of bacterial species including Escherichia coli, the model pathogen Salmonella, the nitrogen-fixing alphaproteobacterium Sinorhizobium meliloti, marine cyanobacteria, Francisella tularensis (the causative agent of tularaemia), Streptococcus pyogenes, the pathogen Staphylococcus aureus, and the plant pathogen Xanthomonas oryzae pathovar oryzae. (
  • MicF in E. coli was found to regulate the expression of a key structural gene that makes up the outer membrane of the E. coli cell. (
  • Filip C, Fletcher G, Wulff JL, Earhart CF. Solubilization of the cytoplasmic membrane of Escherichia coli by the ionic detergent sodium-lauryl sarcosinate. (
  • In this study we report that the outer membrane component lipopolysaccharide (LPS) plays a crucial role for the antimicrobial susceptibility of E. coli BW25113 against the cationic AMPs Cap18, Cap11, Cap11-1-18m 2 , melittin, indolicidin, cecropin P1, cecropin B, and the polypeptide antibiotic colistin, whereas the outer membrane protease OmpT and the lipoprotein Lpp only play a minor role for the susceptibility against cationic AMPs. (
  • Do the amino acid sequence identities of residues that make contact across protein interfaces covary during evolution? (
  • FHIPEP proteins have all about 700 amino acid residues. (
  • A key step in oxidative protein folding is the formation of disulfide bonds, which covalently link the side chains of pairs of Cys residues, impart thermodynamic and mechanical stability to proteins, and control protein folding and activity [ 2 ]. (
  • PDI directly transfers a disulfide to two Cys residues of a substrate protein by means of a thiol-disulfide exchange reaction. (
  • The exclusive detection of PTMs on lysine residues within LipL32 from in vivo-isolated L. interrogans implies that infection-generated modification of leptospiral proteins may have a biologically relevant function during the course of infection. (
  • The structurally characterized members of this functional superfamily usually consist of homotrimeric proteins with subunits that are of 250-450 amino acyl residues in length. (
  • With the survey of experimentally known amino acid sequences and structures, the characteristic features of amino acid residues in β-barrel membrane proteins and novel parameters for understanding their folding and stability have been described by Gromiha and Suwa ( 2007 ). (
  • All forms of A-protein were found to activate the secretion of tumour necrosis factor alpha from murine macrophage. (
  • Cell Viability, Cytoskeleton Organization and Cytokines Secretion of RAW 264.7 Macrophages Exposed to Gram-Negative Bacterial Components. (
  • In biological membranes, various protein secretion devices function as nanomachines, and measuring the internal movements of their component parts is a major technological challenge. (
  • Perhaps erroneously, proteins called 'autotransporters' have long been thought to be one of these protein secretion systems. (
  • The 6S RNA binds to RNA polymerase and regulates transcription, tmRNA has functions in protein synthesis, including the recycling of stalled ribosomes, 4.5S RNA regulates signal recognition particle (SRP), which is required for the secretion of proteins and RNase P is involved in maturing tRNAs. (
  • His research interests are the pathogenesis and molecular epidemiology of bacterial meningitis. (
  • It can, therefore, be concluded that outer membrane proteins play a significant role in the pathogenesis of pasteurellosis. (
  • The recent use of classical bacterial genetics for the analysis of microbial pathogenesis has allowed the identification of loci previously not recognized as virulence determinants. (
  • The study of bacterial pathogenesis has as one of its goals the identification of all determinants that can be targeted for the prevention or treatment of disease. (
  • Autotransporters are bacterial virulence factors critical for the pathogenesis of many organisms. (
  • The periplasm is the cellular compartment between the inner and outer membranes. (
  • The direction of protein transport is from the periplasm to the extracellular environment. (
  • The inner membrane (IM), which surrounds the cytoplasm, is separated from the outer membrane (OM) by an aqueous compartment known as the periplasm ( 1 , 2 ). (
  • The former have a single bilayer with an enveloping peptidoglycan cell wall protecting the bacterium, whereas the latter have two cell membranes separated by a periplasm region, within which is the cell wall. (
  • To get energy for this task, they utilize an inner membrane protein, TonB, that couples across the periplasm to an outer membrane transporter for import of, e.g., vitamin B12 or iron extracted from human transferrin. (
  • Once in the periplasm, binding proteins adsorb ferric siderophores and deliver them to inner membrane (IM) permeases that actively transport either the metal complex or free iron into the cytoplasm. (
  • The space in between IM and OM is an aqueous compartment, the periplasm, which contains a peptidoglycan layer, a large cell polymer that surrounds the bacterial cell [ 8 , 9 ]. (
  • The nanocomposite matrices were optimized for SDS-PAGE with water-soluble molecular weight marker proteins. (
  • Sodium dodecyl sulfate-polyacrylamide gel electrophoresis ( SDS-PAGE ) is a versatile technique used to separate proteins based on their molecular weight differences ( Chrambach and Rodbard, 1971 ). (
  • The success of SDS-PAGE relies on the expectation that all proteins in the analyte have nearly equal detergent loading and adopt similar shapes after SDS treatment as that of the molecular weight marker proteins used for calibration ( Chrambach and Rodbard, 1971 ). (
  • Recombinant A-protein was compared by biochemical, immunological and molecular methods with the A-protein isolated from atypical A. salmonicida bacterial cells by the glycine and the membrane extraction methods. (
  • Molecular basis for activation of a catalytic asparagine residue in a self-cleaving bacterial autotransporter. (
  • The reconstituted system provides a powerful new means to study molecular movements in biological membranes, and the technology is widely applicable to studying the dynamics of diverse cellular nanomachines. (
  • The molecular architecture of a 2D crystalline protein barrier with nano-scale pores necessarily affects the diffusion behavior of low-concentration solutes even if they are significantly smaller than the pore size [ 11 , 12 , 13 ]. (
  • Atomistic molecular dynamics (MD) simulations are capable of providing insight into structural details of amyloid ion channels in the membrane at a resolution not achievable experimentally. (
  • We investigate the molecular mechanisms by which the various mitochondrial outer membrane proteins are targeted to mitochondria, inserted into the outer membrane and assembled into functional complexes within the membrane. (
  • To this end we combine methods from chemistry, biochemistry and molecular biology to probe a wide range of chromatin factors including chromatin binding proteins and histone-modifying enzymes. (
  • Molecular Dynamics Simulations of an Engineered T4 Lysozyme Exclude Helix to Sheet Transition, and Provide Insights into Long Distance, Intra‐Protein Switchable Motion. (
  • Bacterial isolates are recovered from sputum and are subjected to molecular typing. (
  • Recently, we have systematically investigated how molecular chaperones interact with the intrinsically disordered protein α-synuclein. (
  • Selective molecular communication between disulfide-generating enzymes and disulfide carrier proteins, which reflects the molecular and structural diversity of disulfide carrier proteins, is key to the efficient transfer of disulfides to specific sets of substrates. (
  • An article in Molecular & Cellular Proteomics introduced a database of protein-protein interactions within herpesvirus-1. (
  • Autoradiography of the polypeptide profiles identified a major surface protein with an apparent subunit molecular weight of 39,500 that was common to each C. trachomatis serotype. (
  • Affinity chromatography showed the binding of the TonB C-domain to other proteins: immobilized TonB-dependent (FepA and colicin B) and TonB-independent (FepAΔ3-17, OmpA, and lysozyme) proteins adsorbed MalE-TonB69C, revealing a general affinity of the C terminus for other proteins. (
  • Bacterial outer membrane proteins have a distinctive beta barrel architecture in which a sheet of polypeptide strands forms a membrane-spanning tubular structure surrounding a water-filled pore. (
  • However, SprA has 36 polypeptide strands, forming an internal pore that is two and a half times larger in cross sectional area than its nearest contender, and easily large enough to allow the passage of the proteins exported by the T9SS. (
  • Here we describe computational methods to model amyloid ion channels containing the β-sheet motif at atomic scale and to calculate toxic pore activity in the membrane. (
  • Then, insertion of the C-terminal translocator domain in the outer membrane forms a hydrophilic pore for the translocation of the passenger domain to the bacterial cell surface. (
  • Chen, Min , Khalid, Syma , Sansom, Mark S.P. and Bayley, Hagan (2008) Outer membrane protein G: engineering a quiet pore for biosensing. (
  • Conversely, the lateral extracellular opening is blocked by the PorV protein in the PorV complex but accessible in the Plug complex. (
  • The protein has a number of 'extracellular loops' that extend into the environment, but their roles in the structure and the activity of LptD are still largely unknown. (
  • built a library of over 3,000 custom antibodies, which are small Y-shaped proteins that can each recognise a specific portion in one of the extracellular loops and potentially incapacitate LptD. (
  • Iron is one target of gram-negative bacterial cell envelope transport systems, and microbes elaborate high-affinity siderophores that complex extracellular iron ( 70 ). (
  • Vibrio mimicus (Vm) haemagglutinins (HAs), such as an extracellular HA/protease (Vm-HA/protease) and a major outer membrane protein-HA (Vm-OMPHA), have been recognized as the putative adherence factors for the bacterium. (
  • Because ChvG regulates unlinked acid-inducible genes encoding different functions in different ways, we hypothesize that ChvG is a global sensor protein that can directly or indirectly sense extracellular acidity. (
  • Surface bacterial structures, cell wall and cytoplasmic membrane, surround each bacterial cell and create selective barriers between the cell interior and the outside world. (
  • Organic pollutants are able to penetrate into cytoplasmic membrane and affect membrane physiological functions. (
  • This review deals with various adaptation mechanisms of bacterial cell concerning primarily the changes in cytoplasmic membrane and cell wall. (
  • Fluidity of cytoplasmic membrane is a very important characteristic of the membrane structure and is defined as the reciprocal value of its viscosity. (
  • Outside of the universally conserved cytoplasmic membrane, prokaryotes have developed complex architectures, collectively named the cell wall, which provide additional strength, contribute to the cell shape determination, and allow them to face unpredictable and often hostile environmental insults [ 1 , 2 , 3 ]. (
  • Examination of 18 complete and 6 partial sequences of the major outer-membrane protein from 24 chlamydiae isolates was used to reconstruct their evolutionary relationships. (
  • 6) There are estimated to be 185 amino acid positions that are invariable (as opposed to unvaried) in the major outer-membrane protein. (
  • Based on the data, we propose that OpmG is a major outer membrane efflux channel involved in aminoglycoside efflux in P. aeruginosa PAK and that OpmI, its most related paralog, may share an overlapping function. (
  • Unique glycoproteins and major outer membrane proteins can be expressed variously using 25 different genes. (
  • Purification and partial characterization of the major outer membrane protein of Chlamydia trachomatis. (
  • Thus, the 39,500-dalton major outer membrane protein is a serogroup antigen of C. trachomatis organisms. (
  • Depletion of LolA caused a severe growth defect, and impaired the outer membrane localization of Lpp and Pal, another outer membrane lipoprotein. (
  • Outer membrane lipoprotein P6 from Haemophilus influenzae. (
  • LipL41 is the third most abundant lipoprotein found in the outer membranes of pathogenic leptospires and has been considered a putative virulence factor. (
  • In contrast, the OM is typically an asymmetric lipid bilayer where the inner leaflet is composed of phospholipids and the outer leaflet is composed mainly of lipopolysaccharide (LPS) ( 5 ). (
  • While it possesses the typical two-tailed phospholipids in its inner leaflet, the outer leaflet is composed of lipopolysaccharides (LPS). (
  • Complementing our previous findings that all three proteins bind phospholipids, results presented here indicate that multi-domain proteins evolved in Proteobacteria for specific functions in maintaining cell envelope homeostasis. (
  • This defect is elevated in cells lacking pldA , which encodes an outer membrane phospholipase that degrades phospholipids in the outer leaflet 14 . (
  • Cell adaptation maintains the membrane fluidity status and ratio between bilayer/nonbilayer phospholipids as well as the efflux of toxic compounds, protein repair mechanisms, and degradation of contaminants. (
  • It can be modulated by the alteration of fatty acids that build membrane phospholipids. (
  • The Biosynthesis and Evolution of Archaeal Membranes and Ether Phospholipids. (
  • The OM is an essential structure that has been extensively studied over the last half century in Proteobacteria phylum and particularly in Enterobacteriaceae , it possesses a peculiar asymmetric structure due to the presence of a complex glycolipid, the lipopolysaccharide (LPS), in the outer leaflet of the lipid bilayer, whereas the inner leaflet is composed of phospholipids. (
  • Part of the outer membrane protein assembly complex (Bam), which is involved in assembly and insertion of beta-barrel proteins into the outer membrane. (
  • The Gram-negative bacterial cell wall component lipopolysaccharide (LPS) is recognized by the noncanonical inflammasome protein caspase-11 in the cytosol of infected host cells and thereby prompts an inflammatory immune response linked to sepsis. (
  • Lipopolysaccharide (LPS) is a unique glycolipid that paves the outer leaflet of the OM. (
  • Proteolytic activation of OMPHA was also achieved with various proteases from bacterial and eukaryotic sources. (
  • Since the number of related copies for eukaryotic proteins tends to be smaller, there are fewer proteins to compare and it is therefore harder to detect 'covariation' when it occurs. (
  • PDIs, which are ubiquitous thiol-disulfide oxidoreductases in all eukaryotic cells, directly donate disulfides to substrate proteins by means of thiol-disulfide exchange reactions. (
  • He has served as the chair of the Gordon Research Seminar on Membranes: Materials & Processes in 2016 and won the Environmental Protection Agency (EPA) Science to Achieve Results (STAR) fellowship from 2014-2016. (
  • LPS molecules have 5-6 acyl tails combined with a chain of sugar molecules stretching out above the membrane (see the figure below). (
  • Lateral interactions between LPS molecules mediated by divalent cations on the surface and packing of hydrocarbon chains in the membrane impede the passage of both hydrophilic and large hydrophobic molecules ( Nikaido, 2003 ). (
  • Proteins are considered the 'workhorse molecules' of life and they are involved in virtually everything that cells do. (
  • Proteins must have the correct shape to function properly, as they often work by binding to other proteins or molecules-much like a key fitting into a lock. (
  • We try to uncover the precise atomic architecture of one of life's key molecules, the protein. (
  • Transport proteins move molecules and ions across the membrane. (
  • β-barrel membrane proteins perform a variety of functions, such as mediating non-specific, passive transport of ions and small molecules, selectively passing molecules like maltose and sucrose, and can form voltage dependent anion channels. (
  • p>This section provides information about the protein and gene name(s) and synonym(s) and about the organism that is the source of the protein sequence. (
  • section indicates the name(s) of the gene(s) that code for the protein sequence(s) described in the entry. (
  • They consist of two protein components: a sensor that monitors some environmental parameter and a response regulator that mediates a change in gene expression in response to sensor signals. (
  • The great diversity in outer membrane protein genes is thought to originate from gene duplication events, followed by the fusion and fission of resulting paralogs of the gene. (
  • These different copies and fragments of membrane proteins can then recombine, through a process called gene conversion, resulting in a new gene variant. (
  • Reversible protein phosphorylation is a well-established mechanism of regulating gene expression in response to a variety of environmental stress factors ( 13 ) and in recent years, growing evidence has linked two-component systems as well as serine/threonine/tyrosine kinase signaling to AMR ( 13 ⇓ - 15 ). (
  • Vitamin A had the greatest effect on the structure of the bacterial community and gene expression. (
  • This volume concludes with a focus on computational and comparative genomics approaches, especially network-based methods for predicting physical or functional interactions, and integrative analytical approaches for generating more reliable information on bacterial gene function. (
  • Major oral pathogens in the phylum Bacteroidetes , such as Porphyromonas gingivalis , export these proteins across two cell membranes. (
  • The translocation and assembly module (TAM) is a nanomachine required for virulence of bacterial pathogens. (
  • The combination of tripartite multidrug efflux systems and outer membrane impermeability plays a major role in intrinsic antibiotic resistance in clinically relevant pathogens such as Pseudomonas aeruginosa ( 15 ). (
  • Ehrlichia are obligately intracellular pathogens and are transported between cells through the host cell filopodia during initial stages of infection, whereas, in the final stages of infection the pathogen ruptures the host cell membrane. (
  • In addition, serum and sputum samples are being studied to learn about systemic and mucosal immune responses to bacterial pathogens. (
  • The discovery of the TAM provides a new target for the development of therapies to inhibit colonization by bacterial pathogens. (
  • The Impact of 18 Ancestral and Horizontally-Acquired Regulatory Proteins upon the Transcriptome and sRNA Landscape of Salmonella enterica serovar Typhimurium PLoS Genetics, 12, e1006258. (
  • Long thought to be the sole LPS sensor in mammals, TLR4 has been studied in great detail, leading to the discovery and characterization of several auxiliary proteins required for the activation of TLR4 signaling ( 2 ). (
  • We have reconstituted a membrane containing the TAM onto a gold surface for characterization by quartz crystal microbalance with dissipation (QCM-D) and magnetic contrast neutron reflectrometry (MCNR). (
  • Characterization of folding-sensitive nanobodies as tools to study the expression and quality of protein particle immunogens. (
  • While the characterization of resistance genes was already made possible by advances in functional metagenomic approaches, these methods cannot quantify proteins and decipher the potential bacterial signaling cascades involved in AMR. (
  • Preparation and Characterization of Biodegradable poly(isobutylcyano acrylate) Nanoparticles with the Surface Modified by the Adsorption of Proteins", Colloids and Surfaces B: Biointerfaces, vol. 4, 1995, pp. 349-356. (
  • Nuclease colicins such as ColE9 ( brown ) contain a hairpin receptor-binding (R−) domain, an N-terminal translocation (T−) domain that includes the intrinsically unstructured translocation domain (IUTD), shown as a dotted line, and a C-terminal cytotoxic DNase domain to which is bound the immunity protein Im9 ( yellow ). (
  • Dr Joel Selkrig (Lithgow Lab) and colleagues have discovered a novel protein transport system, the translocation and assembly module (TAM). (
  • Lipid-protein interactions within the simulations were analyzed and revealed that aromatic side-chains (Trp, Tyr) of OprF interact with lipid headgroups. (
  • Probably involved in transient protein interactions. (
  • In contrast to this rich body of work for monomeric proteins, relatively little is known about the utility of such statistical models in predicting protein-protein interactions. (
  • Peripheral membrane proteins are temporarily attached either to the lipid bilayer or to integral proteins by a combination of hydrophobic , electrostatic , and other non-covalent interactions. (
  • Lipid-protein Interactions. (
  • Lipid-protein Interactions Determining Membrane Fluidity in Prokaryotes and Eukaryotes. (
  • Electron microscopy density of the PorV (left) and Plug (right) Type 9 protein translocon complexes. (
  • We have proposed that energy is transduced through a mechanical coupling between the inner and outer membrane complexes, supported by simulations that demonstrate the strength of the TonB-transporter connection mediated by hydrogen bonds, as well as the response of the transporter to the application of force. (
  • OM transport of metal complexes and susceptibility to phages and colicins require metabolic energy ( 13 , 25 , 85 ) and usually involve participation of an additional cell envelope protein, TonB. (
  • We find that residue pairs identified using a pseudo-likelihood-based method to covary across protein-protein interfaces in the 50S ribosomal unit and 28 additional bacterial protein complexes with known structure are almost always in contact in the complex, provided that the number of aligned sequences is greater than the average length of the two proteins. (
  • and solving the structures of these complexes can be challenging, even if the structures of the protein subunits are known. (
  • went on to predict the amino acids on the protein-protein interfaces for another 36 bacterial protein complexes with unknown structures, and to present models for four larger complexes. (
  • Morphologically these chlamydial outer membrane complexes (COMC) resembled intact chlamydial EB outer membranes. (
  • The best-studied multi-MCE domain-containing protein is multivalent adhesion molecule 7 (MAM-7) in Vibrio parahaemolyticus , which is an orthologue of YebT. (
  • This membrane contains a diverse set of proteins that are synthesized in the cytosol and harbor signals that are essential for their subsequent import into mitochondria. (
  • This review focuses on recent advances in our understanding of the mechanisms and functions of the various disulfide transfer pathways involved in oxidative protein folding in the ER, chloroplasts, and mitochondria of plants. (
  • Contributions of Membrane Lipids to Bacterial Cell Homeostasis Upon Osmotic Challenge. (
  • Hopanoids and Membrane Integrity and pH Homeostasis. (
  • Membrane Homeostasis Upon Nutrient (C, N, P) Limitation. (
  • Membrane Homeostasis upon pH Challenge. (
  • This volume brings together the most widely used and important protocols currently being employed in researching and understanding bacterial cell wall homeostasis. (
  • Thorough and cutting-edge, Bacterial Cell Wall Homeostasis: Methods and Protocols emphasizes the diversity of the research taking place in bacterial cell wall homeostasis, and explains how the integration of information from across multiple disciplines is going to be essential if a holistic understanding of this important process is to be obtained. (
  • can serve as a road map to study other membrane proteins in their native cellular environment. (
  • Despite their heterogeneity, all classic prion diseases are characterized by the presence of an abnormal isoform of the normal cellular prion protein (PrP C ), which predominantly accumulates in the central nervous system ( 1 ). (
  • S-layer proteins (SLPs) are generally 40-200 kDa and represent up to 15% of total cellular protein production [ 4 ]. (
  • The study of bacterial cellular signaling in AMR and AMR acquisition could thus provide opportunities for the development of new therapeutic strategies. (
  • This cellular exoskeleton is the main structure responsible for the cell shape and the mechanical strength and elasticity of the bacterial envelope [ 10 ]. (
  • Surfactant-Free Anionic PLA Nanoparticles Coated with HIV-1 p24 Protein Induced Cellular and Humoral Immune Responses in Various Animal Models," Journal of Controlled Release, vol. 112, 2006, pp. 175-185. (
  • Vibrio parahaemolyticus sodium-type flagellar protein motY [ PMID: 8636046 , PMID: 15866878 ]. (
  • Alternatively amino acids within membrane-spanning regions of the protein are found to be under purifying selection most likely as a result of structural constraints. (
  • Despite exceptional sequence diversity, S-layer proteins (SLPs) share important characteristics such as their ability to form crystalline sheets punctuated with nano-scale pores, and their propensity for charged amino acids, leading to acidic or basic isoelectric points. (
  • Proteins are strings of amino acids that have folded into a specific three-dimensional shape. (
  • noticed that when a pair of amino acids (one from each protein in a two-protein complex) co-varied, these two amino acids tended to make contact with each other at the protein-protein interface. (
  • Different methods including hydrophobicity profiles, rule based approach, amino acid properties, neural networks, hidden Markov models etc., predict membrane spanning segments of β-barrel membrane proteins. (
  • Virulence of this bacterium is associated with the production of a paracrystalline outer membrane A-layer protein. (
  • For example, certain virulence factors are secreted through the use of so-called "auto-transporters", proteins that export themselves! (
  • A sensor protein ChvG is part of a chromosomally encoded two-component regulatory system ChvG/ChvI that is important for the virulence of Agrobacterium tumefaciens . (
  • 10 ) used Tn phoA to identify insertion mutations in genes that encode proteins with extracytoplasmic domains, the rationale being that certain virulence determinants are likely to be associated with the cell envelope. (
  • Bacterial sRNAs affect how genes are expressed within bacterial cells via interaction with mRNA or protein, and thus can affect a variety of bacterial functions like metabolism, virulence, environmental stress response, and structure. (
  • LipL41 is encoded on the large chromosome 28 bp upstream of a small open reading frame encoding a hypothetical protein of unknown function. (
  • They include integral membrane proteins that are permanently anchored or part of the membrane and peripheral membrane proteins that are only temporarily attached to the lipid bilayer or to other integral proteins. (
  • Modeling and simulations of a bacterial outer membrane protein: OprF from Pseudomonas aeruginosa. (
  • Prion diseases are neurodegenerative conditions associated with a misfolded and infectious protein, scrapie prion protein (PrP Sc ). (
  • The Ehrlichia genome contains many different variants of genes that encode outer membrane proteins. (
  • The inner & outer core composition varies within and between species (B) a standard, amphiphilic, phospholipid bilayer. (
  • As such, when pairs of interacting proteins from different species are compared, there will be many positions in the two proteins that vary. (
  • Bacteroides vulgatus , a bacterial species positively correlated with host growth in gnotobiotic mouse models of postnatal human microbiota development, had the biggest response to vitamin A deficiency, exhibiting an increase in its abundance. (
  • Therefore, we established a community of cultured, sequenced human gut-derived bacterial species in gnotobiotic mice and fed the animals a defined micronutrient-sufficient diet, followed by a derivative diet devoid of vitamin A, folate, iron, or zinc, followed by return to the sufficient diet. (
  • This book focuses on innovative experimental and computational approaches for charting interaction networks in bacterial species. (
  • The book will enable the microbiology community to create substantive resources for addressing many pending unanswered questions, and facilitate the development of new technologies that can be applied to other bacterial species lacking experimental data. (
  • Genetic, multi-omic, and pharmacologic analyses indicated that retinol treatment affected B. vulgatus fitness through the activity of the bacterial AcrAB-TolC efflux system. (
  • This protein is known to bind the T9SS substrate proteins at the cell surface following transport. (
  • Membrane proteins are the key components of cell membranes responsible for a range of structural, regulatory, transportation, energy utilization and enzymatic functions. (
  • They constitute about 30% of total protein content in a single cell and serve as targets for about 50% of commercial drugs (Handbook from GE healthcare). (
  • Imaging bacterial cells in which the native SprA protein was tagged with a fluorescent dye showed that there are only around ten copies of the protein in a cell. (
  • MAM-7 is reported to be an integral outer membrane protein on the cell surface that acts as an adhesin by binding to mammalian cells via phosphatidic acid and fibronectin 22 . (
  • The activity of the latter constructs, which localized GFP in the cytoplasm and TonB in the cell envelope, indicate that the TonB N terminus remains in the inner membrane during its biological function. (
  • Together, these findings infer that the TonB N terminus remains associated with the inner membrane, while the downstream region bridges the cell envelope from the affinity of the C terminus for peptidoglycan. (
  • It is essential for bacterial cell viability and plays an integral function in the positioning and folding of other outer membrane proteins into the bacterial outer membrane. (
  • Combining our data with observations made with bacteriophage-lambda we conclude that the sugar residence time is much more sensitive to (and is decreased by) voltages that are negative from the intra-cell side of the bacterial membrane. (
  • Monsonego A, Zota V, Karni A, Krieger JI, Bar-Or A, Bitan G, Budson AE, Sperling R, Selkoe DJ, Weiner HL (2003) Increased T cell reactivity to amyloid beta protein in older humans and patients with Alzheimer disease. (
  • Virus (blue) binding to a cell membrane (grey) with receptors (orange). (
  • In addition, based on their structure, we try to deduce how receptor proteins on the cell surface do their jobs of relaying information from the outside to the inside of the cell. (
  • Three characterized MDR transporters of P. aeruginosa are known to share this structure, which consists of (i) an inner membrane pump-proton antiporter of the resistance-nodulation-cell division (RND) family (e.g. (
  • Environmentally induced perturbations in cell membrane structure may result in significant disturbance of some physiological functions. (
  • Cell-contact-dependent Outer Membrane Exchange in Myxobacteria. (
  • Role of Lipid Domains in Bacterial Cell Processes. (
  • Collagen-binding outer membrane protein forming a fibrillar matrix on the bacterial cell surface. (
  • As a result it has a thinner cell wall with an outer membrane largely composed of LPS. (
  • The present invention relates to Chimeric Antigen Receptors (CAR) that are recombinant chimeric proteins able to redirect immune cell specificity and. (
  • Exactly how they are assembled onto the bacterial cell surface remains contentious. (
  • and methods for analyzing the non-protein components of the cell wall and the increasing use of computational approaches for predicting and modeling cell wall related functions and processes. (
  • A TolC-Like Protein Is Required for Heterocyst Development in Anabaena sp. (
  • Outer membrane protein P.III/class IV from Neisseria. (
  • Neisseria meningitidis has become a leading cause of bacterial meningitis in the United States after dramatic reductions in the incidence of Streptococcus pneumoniae ( 1 ) and Haemophilus influenzae type b (Hib) ( 2 ) infections have been achieved as a result of using conjugate vaccines. (
  • Vaccination against Neisseria meningitidis, a leading cause of bacterial meningitis, can be costly because researchers must grow the bacterium in culture to isolate oligosaccharide antigens. (
  • An outer membrane protein of Neisseria meningitidis group B responsible for serotype specificity. (
  • The MCNR studies provided structural resolution down to 1 A, enabling accurate measurement of protein domains projecting from the membrane layer. (
  • Here, we offer a rationale for charged S-layer proteins in the context of the structural evolution of S-layers. (
  • Jang H, Arce FT, Ramachandran S, Kagan BL, Lal R, Nussinov R (2014) Disordered amyloidogenic peptides may insert into the membrane and assemble into common cyclic structural motifs. (
  • Understanding the structural features of β-barrel membrane proteins and detecting them in genomic sequences are challenging tasks in structural and functional genomics. (
  • It also covers the structural approaches required to understand bacterial intramembrane proteolysis and the structure and function of bacterial proteins involved in surface polysaccharides, outer membrane, and envelope assembly. (
  • p>This section provides any useful information about the protein, mostly biological knowledge. (
  • Membrane proteins are proteins that interact with, or are part of, biological membranes . (
  • Such proteins can be separated from the biological membranes only using detergents , nonpolar solvents , or sometimes denaturing agents. (
  • The importance of such a structure is underlined by the notion that everything that exists outside of the biological membrane is non-living. (
  • First, the mechanisms, theory, and structures for electron transfer in biological systems are provided, followed by analysis of the strategies and structures engineered in redox-protein devices. (
  • Similarities have been demonstrated between MCE domains and the substrate binding proteins of ABC transporters 4 . (
  • The NRLBM gives access to a collection of over 10,000 bacterial isolates form patients and carriers and of human clinical specimen (liquor and serum). (
  • Protein band of 69 kDa was present only in four of the field isolates and vaccine strain whereas OMP with 43 kDa was detected in only four of the field isolates and absent in remaining field isolates and vaccine strain. (
  • These studies are elucidating the dynamics of respiratory tract bacterial colonization. (
  • Typhimurium-derived vaccine antigens and influenza A virus (IAV)-derived vaccine antigens within or on the outer membrane of Bt OMVs. (
  • Bacterial outer membrane proteins (OMP) were selected as target antigens. (
  • To that end, outer membrane proteins have been identified and are being evaluated as potential vaccine antigens. (
  • Based on contact angle measurements of the composite hydrogels, the improved resolution of membrane proteins is attributed to the more hydrophobic environment rendered by carbon nanotubes and graphene. (
  • The present results could be useful to develop more hydrophobic nanocomposite gels exclusively for electrophoretic separation of membrane proteins isolated from different sources. (
  • The team made the educated guess that a large T9SS component in the outer membrane with no sequence similarity to proteins of known function, called SprA, was likely to be the T9SS translocon. (
  • Note that the 'protein existence' evidence does not give information on the accuracy or correctness of the sequence(s) displayed. (
  • Bairoch, A., Apweiler, R.: The SWISS-PROT protein sequence database and its supplement TrEMBL. (
  • These were the flagellar hook protein FlgE, flagellar hook-associated protein 1, flagellar hook-associated protein, flagellin, and flagellar hook-filament junction protein FlgL. (
  • This data indicates that C. malonaticus flagellar proteins may have an important role in the organism's invasion properties. (
  • The discovery of GBPs as regulators of OMV-mediated inflammation paves the way toward a mechanistic understanding of the host response toward bacterial OMVs and may lead to effective strategies to ameliorate inflammation induced by bacterial infections. (
  • IL-22 Controls Iron-Dependent Nutritional Immunity Against Systemic Bacterial Infections Science Immunology, 2, eaai8371. (
  • This approach will aid in the development of more efficient vaccines against bacterial infections affecting the aquaculture industry. (
  • Size fractionation of bacterial capsular polysaccharides for their use in conjugate vaccines," Vaccine, vol. 17 No. 9-10, pp. 1251-1263 (Mar. 1999). (
  • This architecture suggests a membrane surveillance model of action, in which TonB finds occupied receptor proteins by surveying the underside of peptidoglycan-associated outer membrane proteins. (
  • Membrane receptor proteins relay signals between the cell's internal and external environments. (
  • Modeling Lipid Membranes. (
  • 2020. "Disulfide Bonds Affect the Binding Sites of Human β Defensin Type 3 On Negatively Charged Lipid Membranes. (
  • [4] It is estimated that 20-30% of all genes in most genomes encode membrane proteins. (
  • Domene Nunez, C , Bond, PJ & Sansom, MSP 2003, ' Membrane protein simulations: Ion channels and bacterial outer membrane proteins ', Advances in Protein Chemistry , vol. 66, pp. 159-193. (
  • The simulations help to explain the mechanism of formation of low conductance pores within the outer membrane. (
  • Accelerating Membrane Simulations with Hydrogen Mass Repartitioning. (
  • A protein called LptD is embedded in the outer membrane, where it inserts new lipopolysaccharides. (
  • Players in the Nonpolar Lipid Game - Proteins Involved in Nonpolar Lipid Metabolism in Yeast. (