Homoserine4-Butyrolactone: One of the FURANS with a carbonyl thereby forming a cyclic lactone. It is an endogenous compound made from gamma-aminobutyrate and is the precursor of gamma-hydroxybutyrate. It is also used as a pharmacological agent and solvent.Homoserine O-Succinyltransferase: The first enzyme in the METHIONINE biosynthetic pathway, this enzyme catalyzes the succinylation reaction of L-homoserine to O-succinyl-L-homoserine and COENZYME A using succinyl-CoA.Acyl-Butyrolactones: Cyclic esters of acylated BUTYRIC ACID containing four carbons in the ring.Quorum Sensing: A phenomenon where microorganisms communicate and coordinate their behavior by the accumulation of signaling molecules. A reaction occurs when a substance accumulates to a sufficient concentration. This is most commonly seen in bacteria.Aspartate Kinase: An enzyme that catalyzes the formation of beta-aspartyl phosphate from aspartic acid and ATP. Threonine serves as an allosteric regulator of this enzyme to control the biosynthetic pathway from aspartic acid to threonine. EC 2.7.2.4.Chromobacterium: A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria occurring in soil and water. Its organisms are generally nonpathogenic, but some species do cause infections of mammals, including humans.Threonine: An essential amino acid occurring naturally in the L-form, which is the active form. It is found in eggs, milk, gelatin, and other proteins.Aspartate-Semialdehyde Dehydrogenase: An enzyme that catalyzes the conversion of L-aspartate 4-semialdehyde, orthophosphate, and NADP+ to yield L-4-aspartyl phosphate and NADPH. EC 1.2.1.11.Carbon-Oxygen Lyases: Enzymes that catalyze the cleavage of a carbon-oxygen bond by means other than hydrolysis or oxidation. EC 4.2.Laminaria: A genus of BROWN ALGAE in the family Laminariaceae. Dried pencil-like pieces may be inserted in the cervix where they swell as they absorb moisture, serving as osmotic dilators.Pseudomonas aeruginosa: 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.Gene Expression Regulation, Bacterial: Any of the processes by which cytoplasmic or intercellular factors influence the differential control of gene action in bacteria.Phosphotransferases: A rather large group of enzymes comprising not only those transferring phosphate but also diphosphate, nucleotidyl residues, and others. These have also been subdivided according to the acceptor group. (From Enzyme Nomenclature, 1992) EC 2.7.Bacterial Proteins: Proteins found in any species of bacterium.Bromates: Negative ions or salts derived from bromic acid, HBrO3.Pectobacterium carotovorum: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria that causes rotting, particularly of storage tissues, of a wide variety of plants and causes a vascular disease in CARROTS; and POTATO plants.Carbon-Sulfur Ligases: Enzymes that catalyze the joining of two molecules by the formation of a carbon-sulfur bond. EC 6.2.Phosphotransferases (Alcohol Group Acceptor): A group of enzymes that transfers a phosphate group onto an alcohol group acceptor. EC 2.7.1.Lactones: Cyclic esters of hydroxy carboxylic acids, containing a 1-oxacycloalkan-2-one structure. Large cyclic lactones of over a dozen atoms are MACROLIDES.Hafnia alvei: The type species for the genus HAFNIA. It is distinguished from other biochemically similar bacteria by its lack of acid production on media containing sucrose. (From Bergey's Manual of Determinative Bacteriology, 9th ed)Methionine: A sulfur-containing essential L-amino acid that is important in many body functions.Pectobacterium: A genus of gram-negative bacteria in the family ENTEROBACTERIACEAE consisting of species that profusely produce pectinolytic enzymes in plant pathogenesis.Vibrio: A genus of VIBRIONACEAE, made up of short, slightly curved, motile, gram-negative rods. Various species produce cholera and other gastrointestinal disorders as well as abortion in sheep and cattle.Carboxylic Ester Hydrolases: Enzymes which catalyze the hydrolysis of carboxylic acid esters with the formation of an alcohol and a carboxylic acid anion.Ochrobactrum: A genus of the family BRUCELLACEAE comprising obligately aerobic gram-negative rods with parallel sides and rounded ends.Alcohol Oxidoreductases: A subclass of enzymes which includes all dehydrogenases acting on primary and secondary alcohols as well as hemiacetals. They are further classified according to the acceptor which can be NAD+ or NADP+ (subclass 1.1.1), cytochrome (1.1.2), oxygen (1.1.3), quinone (1.1.5), or another acceptor (1.1.99).Serratia: A genus of gram-negative, facultatively anaerobic, rod-shaped bacteria that occurs in the natural environment (soil, water, and plant surfaces) or as an opportunistic human pathogen.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.Brevibacterium: A gram-positive organism found in dairy products, fresh and salt water, marine organisms, insects, and decaying organic matter.Dodecanol: A saturated 12-carbon fatty alcohol obtained from coconut oil fatty acids. It has a floral odor and is used in detergents, lubricating oils, and pharmaceuticals. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Agrobacterium tumefaciens: A species of gram-negative, aerobic bacteria isolated from soil and the stems, leafs, and roots of plants. Some biotypes are pathogenic and cause the formation of PLANT TUMORS in a wide variety of higher plants. The species is a major research tool in biotechnology.Lyases: A class of enzymes that catalyze the cleavage of C-C, C-O, and C-N, and other bonds by other means than by hydrolysis or oxidation. (Enzyme Nomenclature, 1992) EC 4.Biofilms: Encrustations, formed from microbes (bacteria, algae, fungi, plankton, or protozoa) embedding in extracellular polymers, that adhere to surfaces such as teeth (DENTAL DEPOSITS); PROSTHESES AND IMPLANTS; and catheters. Biofilms are prevented from forming by treating surfaces with DENTIFRICES; DISINFECTANTS; ANTI-INFECTIVE AGENTS; and antifouling agents.Corynebacterium: A genus of asporogenous bacteria that is widely distributed in nature. Its organisms appear as straight to slightly curved rods and are known to be human and animal parasites and pathogens.S-Adenosylmethionine: Physiologic methyl radical donor involved in enzymatic transmethylation reactions and present in all living organisms. It possesses anti-inflammatory activity and has been used in treatment of chronic liver disease. (From Merck, 11th ed)Pyocyanine: Antibiotic pigment produced by Pseudomonas aeruginosa.Molecular Sequence Data: 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.Ligases: A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor. (Dorland, 28th ed) EC 6.Chromatography, Thin Layer: Chromatography on thin layers of adsorbents rather than in columns. The adsorbent can be alumina, silica gel, silicates, charcoals, or cellulose. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)NitrosoguanidinesCulture Media: Any liquid or solid preparation made specifically for the growth, storage, or transport of microorganisms or other types of cells. The variety of media that exist allow for the culturing of specific microorganisms and cell types, such as differential media, selective media, test media, and defined media. Solid media consist of liquid media that have been solidified with an agent such as AGAR or GELATIN.Aspartic Acid: One of the non-essential amino acids commonly occurring in the L-form. It is found in animals and plants, especially in sugar cane and sugar beets. It may be a neurotransmitter.Genes, Bacterial: The functional hereditary units of BACTERIA.Exopeptidases: A sub-class of PEPTIDE HYDROLASES that act only near the ends of polypeptide chains.Acetyltransferases: Enzymes catalyzing the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound. EC 2.3.1.Serratia marcescens: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria found in soil, water, food, and clinical specimens. It is a prominent opportunistic pathogen for hospitalized patients.Enzyme Repression: The interference in synthesis of an enzyme due to the elevated level of an effector substance, usually a metabolite, whose presence would cause depression of the gene responsible for enzyme synthesis.Amino Acid Sequence: 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.Sinorhizobium meliloti: A species of gram-negative, aerobic bacteria that causes formation of root nodules on some, but not all, types of sweet clover, MEDICAGO SATIVA, and fenugreek.Hydrogen Cyanide: Hydrogen cyanide (HCN); A toxic liquid or colorless gas. It is found in the smoke of various tobacco products and released by combustion of nitrogen-containing organic materials.Cloning, Molecular: 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.Cetrimonium Compounds: Cetyltrimethylammonium compounds that have cationic detergent, antiseptic, and disinfectant activities. They are used in pharmaceuticals, foods, and cosmetics as preservatives; on skin, mucous membranes, etc., as antiseptics or cleansers, and also as emulsifiers. These compounds are toxic when used orally due to neuromuscular blockade.Acylation: The addition of an organic acid radical into a molecule.Burkholderia cenocepacia: A species of gram-negative bacteria that causes disease in plants. It is found commonly in the environment and is an opportunistic pathogen in humans.Pseudomonas putida: A species of gram-negative, aerobic bacteria isolated from soil and water as well as clinical specimens. Occasionally it is an opportunistic pathogen.Nitrosomonadaceae: A family of gram-negative nitrifying bacteria, in the order Nitrosomonadales, class BETAPROTEOBACTERIA.Amino Acids: Organic compounds that generally contain an amino (-NH2) and a carboxyl (-COOH) group. Twenty alpha-amino acids are the subunits which are polymerized to form proteins.Mutation: 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.DNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Isoleucine: An essential branched-chain aliphatic amino acid found in many proteins. It is an isomer of LEUCINE. It is important in hemoglobin synthesis and regulation of blood sugar and energy levels.Burkholderia: A genus of gram-negative, aerobic, rod-shaped bacteria. Organisms in this genus had originally been classified as members of the PSEUDOMONAS genus but overwhelming biochemical and chemical findings indicated the need to separate them from other Pseudomonas species, and hence, this new genus was created.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Rhizobium leguminosarum: A species of gram-negative, aerobic bacteria that is found in soil and which causes formation of root nodules on some, but not all, types of field pea, lentil, kidney bean, and clover.Kinetics: The rate dynamics in chemical or physical systems.Trans-Activators: Diffusible gene products that act on homologous or heterologous molecules of viral or cellular DNA to regulate the expression of proteins.Luminescent Measurements: Techniques used for determining the values of photometric parameters of light resulting from LUMINESCENCE.Burkholderia cepacia: A species of BURKHOLDERIA considered to be an opportunistic human pathogen. It has been associated with various types of infections of nosocomial origin.Virulence Factors: 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)Multienzyme Complexes: Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.Bacillus: A genus of BACILLACEAE that are spore-forming, rod-shaped cells. Most species are saprophytic soil forms with only a few species being pathogenic.Virulence: 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.Plasmids: 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.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Homoserine Dehydrogenase: An enzyme that catalyzes the reduction of aspartic beta-semialdehyde to homoserine, which is the branch point in biosynthesis of methionine, lysine, threonine and leucine from aspartic acid. EC 1.1.1.3.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Serine: A non-essential amino acid occurring in natural form as the L-isomer. It is synthesized from GLYCINE or THREONINE. It is involved in the biosynthesis of PURINES; PYRIMIDINES; and other amino acids.Biosensing Techniques: Any of a variety of procedures which use biomolecular probes to measure the presence or concentration of biological molecules, biological structures, microorganisms, etc., by translating a biochemical interaction at the probe surface into a quantifiable physical signal.Hydro-Lyases: Enzymes that catalyze the breakage of a carbon-oxygen bond leading to unsaturated products via the removal of water. EC 4.2.1.Aspartokinase Homoserine Dehydrogenase: A bifunctional protein consisting of aspartokinase, and homoserine dehydrogenase activities. It is found primarily in BACTERIA and in PLANTS.Acyl Carrier Protein: Consists of a polypeptide chain and 4'-phosphopantetheine linked to a serine residue by a phosphodiester bond. Acyl groups are bound as thiol esters to the pantothenyl group. Acyl carrier protein is involved in every step of fatty acid synthesis by the cytoplasmic system.Operon: In bacteria, a group of metabolically related genes, with a common promoter, whose transcription into a single polycistronic MESSENGER RNA is under the control of an OPERATOR REGION.Feedback: A mechanism of communication within a system in that the input signal generates an output response which returns to influence the continued activity or productivity of that system.Symbiosis: The relationship between two different species of organisms that are interdependent; each gains benefits from the other or a relationship between different species where both of the organisms in question benefit from the presence of the other.Solanum tuberosum: A plant species of the genus SOLANUM, family SOLANACEAE. The starchy roots are used as food. SOLANINE is found in green parts.Acyltransferases: Enzymes from the transferase class that catalyze the transfer of acyl groups from donor to acceptor, forming either esters or amides. (From Enzyme Nomenclature 1992) EC 2.3.Hypochlorous Acid: An oxyacid of chlorine (HClO) containing monovalent chlorine that acts as an oxidizing or reducing agent.Genetic Complementation Test: A test used to determine whether or not complementation (compensation in the form of dominance) will occur in a cell with a given mutant phenotype when another mutant genome, encoding the same mutant phenotype, is introduced into that cell.Chromatography, High Pressure Liquid: Liquid chromatographic techniques which feature high inlet pressures, high sensitivity, and high speed.Substrate Specificity: A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.Siderophores: Low-molecular-weight compounds produced by microorganisms that aid in the transport and sequestration of ferric iron. (The Encyclopedia of Molecular Biology, 1994)Gram-Negative Bacteria: Bacteria which lose crystal violet stain but are stained pink when treated by Gram's method.Plant Diseases: Diseases of plants.Repressor Proteins: Proteins which maintain the transcriptional quiescence of specific GENES or OPERONS. Classical repressor proteins are DNA-binding proteins that are normally bound to the OPERATOR REGION of an operon, or the ENHANCER SEQUENCES of a gene until a signal occurs that causes their release.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Maltose-Binding Proteins: Periplasmic proteins that bind MALTOSE and maltodextrin. They take part in the maltose transport system of BACTERIA.Species Specificity: 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.Cyanogen Bromide: Cyanogen bromide (CNBr). A compound used in molecular biology to digest some proteins and as a coupling reagent for phosphoroamidate or pyrophosphate internucleotide bonds in DNA duplexes.Lysine: An essential amino acid. It is often added to animal feed.Temperature: 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.Pseudomonas Infections: Infections with bacteria of the genus PSEUDOMONAS.Mass Spectrometry: An analytical method used in determining the identity of a chemical based on its mass using mass analyzers/mass spectrometers.

Microbiological degradation of bile acids. The conjugation of a certain cholic acid metabolite with amino acids in Corynebacterium equi. (1/367)

1. (4R)-4[4alpha-(2-Carboxyethyl)-3aalpha-hexahydro-7abeta-methyl-5-oxoindan-1beta-y l]valeric acid (II) could not be utilized by Arthrobacter simplex, even though the acid was one of the metabolites formed from cholic acid (I) by this organism. Therefore the further degradation of the acid (II) by Corynebacterium equi was investigated to identify the intermediates involved in the cholic acid degradation. 2. The organism, cultured in a medium containing the acid (II) as the sole source of carbon, produced unexpected metabolites, the conjugates of this original acid (II) with amino acids or their derivatives, although the yield was very low. These new metabolites were isolated and identified by chemical synthesis as the Na-((4R)-4-[4alpha-(2-carboxyethyl)-3a alpha-hexahydro-7a beta-methyl-5-oxoindan-1 beta-yl]-valeryl) derivatives of L-alanine, glutamic acid, O-acetylhomoserine and glutamine, i.e. compounds (IIIa), (IIIb), (IIId) respectively. 3. The possibility that the bacterial synthetic reaction observed in the acid (II) metabolism with C. equi is analogous to peptide conjugation known in both animals and higher plants is discussed. A possible mechanism for this bacterial conjugation is also considered.  (+info)

Autoinducer binding by the quorum-sensing regulator TraR increases affinity for target promoters in vitro and decreases TraR turnover rates in whole cells. (2/367)

TraR is an Agrobacterium transcriptional regulator whose activity requires the pheromone N-3-oxooctanoyl-L-homoserine lactone. TraR was purified as a complex with the pheromone and contained one pheromone molecule per protein monomer. TraR-pheromone complexes bound to a single DNA site and activated two promoters that flank this site. Promoter expression was elevated 30-fold by using a supercoiled template. Pheromone binding increased the affinity of TraR for this binding site. Pheromone also increased TraR abundance in vivo by causing a 20-fold decrease in TraR turnover rates.  (+info)

Swarming by Pseudomonas syringae B728a requires gacS (lemA) and gacA but not the acyl-homoserine lactone biosynthetic gene ahlI. (3/367)

Pseudomonas syringae pv. syringae B728a, a causal agent of bacterial brown spot on snap beans, swarms with a characteristic dendritic pattern on semisolid (0.4%) agar plates. Filamentation of swarming cells of B728a was not observed. Mutations in either the gacS (formerly lemA) or gacA gene of B728a eliminate the ability of this P. syringae isolate to swarm without obvious effects on bacterial motility. Three field isolates showed a similar dependence on gacS for swarming. Since gacS and gacA mutants are known to be deficient in N-acyl-L-homoserine lactone (acyl-HSL) production, a mutant was constructed by disruption of the ahlI gene of B728a. This mutant did not make any acyl-HSL detectable by the Agrobacterium traG::lacZ reporter system, yet was unaffected in its ability to swarm. Other phenotypes of gacS and gacA mutations were similarly unaffected in the ahlI mutant.  (+info)

The novel transmembrane Escherichia coli proteins involved in the amino acid efflux. (4/367)

A novel gene of Escherichia coli, rhtB, has been characterized. Amplification of this gene provides resistance to homoserine and homoserine lactone. Another E. coli gene, rhtC, provides resistance to threonine. The homologues of RhtB are widely distributed among various eubacteria and archaea, from one to 12 copies of family members that differ in their primary structure were found in the genomes. Most of them are genes that encode hypothetical transmembrane proteins. Experimental data that indicate participation of the rhtB product in the excretion of homoserine have been obtained.  (+info)

Production of acylated homoserine lactones by psychrotrophic members of the Enterobacteriaceae isolated from foods. (5/367)

Bacteria are able to communicate and gene regulation can be mediated through the production of acylated homoserine lactone (AHL) signal molecules. These signals play important roles in several pathogenic and symbiotic bacteria. The following study was undertaken to investigate whether AHLs are produced by bacteria found in food at temperatures and NaCl conditions commercially used for food preservation and storage. A minimum of 116 of 154 psychrotrophic Enterobacteriaceae strains isolated from cold-smoked salmon or vacuum-packed chilled meat produced AHLs. Analysis by thin-layer chromatography indicated that N-3-oxo-hexanoyl homoserine lactone was the major AHL of several of the strains isolated from cold-smoked salmon and meat. AHL-positive strains cultured at 5 degrees C in medium supplemented with 4% NaCl produced detectable amounts of AHL(s) at cell densities of 10(6) CFU/ml. AHLs were detected in cold-smoked salmon inoculated with strains of Enterobacteriaceae stored at 5 degrees C under an N(2) atmosphere when mean cell densities increased to 10(6) CFU/g and above. Similarly, AHLs were detected in uninoculated samples of commercially produced cold-smoked salmon when the level of indigenous Enterobacteriaceae reached 10(6) CFU/g. This level of Enterobacteriaceae is often found in lightly preserved foods, and AHL-mediated gene regulation may play a role in bacteria associated with food spoilage or food toxicity.  (+info)

Characterization of Pseudomonas aeruginosa enoyl-acyl carrier protein reductase (FabI): a target for the antimicrobial triclosan and its role in acylated homoserine lactone synthesis. (6/367)

The Pseudomonas aeruginosa fabI structural gene, encoding enoyl-acyl carrier protein (ACP) reductase, was cloned and sequenced. Nucleotide sequence analysis revealed that fabI is probably the last gene in a transcriptional unit that includes a gene encoding an ATP-binding protein of an ABC transporter of unknown function. The FabI protein was similar in size and primary sequence to other bacterial enoyl-ACP reductases, and it contained signature motifs for the FAD-dependent pyridine nucleotide reductase and glucose/ribitol dehydrogenase families, respectively. The chromosomal fabI gene was disrupted, and the resulting mutant was viable but possessed only 62% of the total enoyl-ACP reductase activity found in wild-type cell extracts. The fabI-encoded enoyl-ACP reductase activity was NADH dependent and inhibited by triclosan; the residual activity in the fabI mutant was also NADH dependent but not inhibited by triclosan. An polyhistidine-tagged FabI protein was purified and characterized. Purified FabI (i) could use NADH but not NADPH as a cofactor; (ii) used both crotonyl-coenzyme A and crotonyl-ACP as substrates, although it was sixfold more active with crotonyl-ACP; and (iii) was efficiently inhibited by low concentrations of triclosan. A FabI Gly95-to-Val active-site amino acid substitution was generated by site-directed mutagenesis, and the mutant protein was purified. The mutant FabI protein retained normal enoyl-ACP reductase activity but was highly triclosan resistant. When coupled to FabI, purified P. aeruginosa N-butyryl-L-homoserine lactone (C4-HSL) synthase, RhlI, could synthesize C4-HSL from crotonyl-ACP and S-adenosylmethionine. This reaction was NADH dependent and inhibited by triclosan. The levels of C4-HSL and N-(3-oxo)-dodecanoyl-L-homoserine lactones were reduced 50% in a fabI mutant, corroborating the role of FabI in acylated homoserine lactone synthesis in vivo.  (+info)

Pathways of assimilative sulfur metabolism in Pseudomonas putida. (7/367)

Cysteine and methionine biosynthesis was studied in Pseudomonas putida S-313 and Pseudomonas aeruginosa PAO1. Both these organisms used direct sulfhydrylation of O-succinylhomoserine for the synthesis of methionine but also contained substantial levels of O-acetylserine sulfhydrylase (cysteine synthase) activity. The enzymes of the transsulfuration pathway (cystathionine gamma-synthase and cystathionine beta-lyase) were expressed at low levels in both pseudomonads but were strongly upregulated during growth with cysteine as the sole sulfur source. In P. aeruginosa, the reverse transsulfuration pathway between homocysteine and cysteine, with cystathionine as the intermediate, allows P. aeruginosa to grow rapidly with methionine as the sole sulfur source. P. putida S-313 also grew well with methionine as the sulfur source, but no cystathionine gamma-lyase, the key enzyme of the reverse transsulfuration pathway, was found in this species. In the absence of the reverse transsulfuration pathway, P. putida desulfurized methionine by the conversion of methionine to methanethiol, catalyzed by methionine gamma-lyase, which was upregulated under these conditions. A transposon mutant of P. putida that was defective in the alkanesulfonatase locus (ssuD) was unable to grow with either methanesulfonate or methionine as the sulfur source. We therefore propose that in P. putida methionine is converted to methanethiol and then oxidized to methanesulfonate. The sulfonate is then desulfonated by alkanesulfonatase to release sulfite for reassimilation into cysteine.  (+info)

Pseudomonas aeruginosa quorum-sensing signal molecule N-(3-oxododecanoyl)-L-homoserine lactone inhibits expression of P2Y receptors in cystic fibrosis tracheal gland cells. (8/367)

ATP and UTP have been proposed for use as therapeutic treatment of the abnormal ion transport in the airway epithelium in cystic fibrosis (CF), the most characteristic feature of which is permanent infection by Pseudomonas aeruginosa. As for diverse gram-negative bacteria, this pathogenic bacterium accumulates diffusible N-acylhomoserine lactone (AHL) signal molecules, and when a threshold concentration is reached, virulence factor genes are activated. Human submucosal tracheal gland serous (HTGS) cells are believed to play a major role in the physiopathology of CF. Since ATP and UTP stimulate CF epithelial cells through P2Y receptors, we sought to determine whether CF HTGS cells are capable of responding to the AHLs N-butanoyl-L-homoserine lactone (BHL), N-hexanoyl-L-homoserine lactone (HHL), N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL), and N-(3-oxohexanoyl)-L-homoserine lactone (OHHL), with special reference to P2Y receptors. All AHLs inhibited ATP- and UTP-induced secretion by CF HTGS cells. The 50% inhibitory concentrations were as high as 10 and 5 microM for BHL and HHL, respectively, but were only 0.3 and 0.4 pM for OdDHL and OHHL, respectively. Furthermore, all AHLs down-regulated the expression of the P2Y2 and P2Y4 receptors. Ibuprofen and nordihydroguaiaretic acid were able to prevent AHL inhibition of the responses to nucleotides, but neither dexamethasone nor indomethacin was able to do this. These data indicate that AHLs may alter responsiveness to ATP and UTP by CF HTGS cells and suggest that, in addition to ATP and/or UTP analogues, ibuprofen may be of use for a combinational pharmacological therapy for CF.  (+info)

*Amino acid kinase

Zhu-Shimoni JX, Galili G (March 1998). "Expression of an arabidopsis aspartate Kinase/Homoserine dehydrogenase gene is ... The metabolic regulation of expression of an Arabidopsis thaliana aspartate kinase/homoserine dehydrogenase (AK/HSD) gene, ...

*Homoserine

... (also called isothreonine) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH2OH. L-Homoserine is not one ... Homoserine, or its lactone form, is the product of a cyanogen bromide cleavage of a peptide by degradation of methionine. ... Homoserine is an intermediate in the biosynthesis of three essential amino acids: methionine, threonine (an isomer of ... homoserine), and isoleucine. It forms by two reductions of aspartic acid via the intermediacy of aspartate semialdehyde. Berg, ...

*Homoserine kinase

In enzymology, a homoserine kinase (EC 2.7.1.39) is an enzyme that catalyzes the chemical reaction ATP + L-homoserine ⇌ {\ ... The systematic name of this enzyme class is ATP:L-homoserine O-phosphotransferase. Other names in common use include homoserine ... Watanabe Y, Konishi S, Shimura K (1957). "Biosynthesis of threonine from homoserine. VI. Homoserine kinase". J. Biochem. 44: ... the two substrates of this enzyme are ATP and L-homoserine, whereas its two products are ADP and O-phospho-L-homoserine. This ...

*Homoserine dehydrogenase

In enzymology, a homoserine dehydrogenase (EC 1.1.1.3) is an enzyme that catalyzes the chemical reaction L-homoserine + NAD(P ... Homoserine dehydrogenase catalyzes the reaction of aspartate-semialdehyde (ASA) to homoserine. The overall reaction reduces the ... dependent reduction of aspartate beta-semialdehyde into homoserine. Homoserine is an intermediate in the biosynthesis of ... Homoserine dehydrogenase has an NAD(P)H cofactor, which then donates a hydrogen to the same carbon, effectively reducing the ...

*Homoserine O-succinyltransferase

Other names in common use include homoserine O-transsuccinylase, and homoserine succinyltransferase. This enzyme participates ... O-succinyl-L-homoserine Thus, the two substrates of this enzyme are succinyl-CoA and L-homoserine, whereas its two products are ... In enzymology, a homoserine O-succinyltransferase (EC 2.3.1.46) is an enzyme that catalyzes the chemical reaction succinyl-CoA ... The systematic name of this enzyme class is succinyl-CoA:L-homoserine O-succinyltransferase. ...

*Acyl-homoserine-lactone synthase

acyl-homoserine lactone synthase, acyl homoserine lactone synthase, acyl-homoserinelactone synthase, acylhomoserine lactone ... N-acyl-L-homoserine lactone Acyl-homoserine lactones (AHLs) are produced by a number of bacterial species and are used by them ... Acyl-homoserine-lactone synthase (EC 2.3.1.184) is an enzyme with systematic name acyl-(acyl-carrier protein):S-adenosyl-L- ... Acyl-homoserine-lactone synthase at the US National Library of Medicine Medical Subject Headings (MeSH) Molecular and Cellular ...

*N-Acyl homoserine lactone

... s (Abbreviated as AHLs or N-AHLs) are a class of signaling molecules involved in bacterial quorum ... Homoserine lactone is also a product of the proteolytic reaction of cyanogen bromide (CNBR) with a methionine residue in a ... Homoserine lactones were first discovered at Cornell University. Lactonase Kumari, A.; Pasini, P.; Deo, S. K.; Flomenhoft, D.; ...

*Homoserine/threonine resistance transporter

The resistance to homoserine/threonine (RhtB) family (TC# 2.A.76) belongs to the lysine exporter (LysE) superfamily of ... The original text was at "2.A.76 The Resistance to Homoserine/Threonine (RhtB) Family". Tsu, Brian V.; Saier, Milton H. (2015- ...

*Acyl-homoserine-lactone acylase

... (EC 3.5.1.97, acyl-homoserine lactone acylase, AHL-acylase, AiiD, N-acyl-homoserine lactone ... L-homoserine lactone + a carboxylate Acyl homoserine lactones (AHLs) are produced by a number of bacterial species . Sio, C.F ... Lin, Y.H.; Xu, J.L.; Hu, J.; Wang, L.H.; Ong, S.L.; Leadbetter, J.R.; Zhang, L.H. (2003). "Acyl-homoserine lactone acylase from ... Acyl-homoserine-lactone acylase at the US National Library of Medicine Medical Subject Headings (MeSH) Molecular and Cellular ...

*Acyl-homoserine lactone acylase

... may refer to: Quorum-quenching N-acyl-homoserine lactonase, an enzyme Acyl-homoserine-lactone ...

*Quorum-quenching N-acyl-homoserine lactonase

N-acyl homoserine lactonase, N-acyl homoserine lactone hydrolase, N-acyl-homoserine lactone lactonase, N-acyl-L-homoserine ... Quorum-quenching N-acyl-homoserine lactonase (EC 3.1.1.81, acyl homoserine degrading enzyme, acyl-homoserine lactone acylase, ... an N-acyl-L-homoserine Acyl-homoserine lactones are produced by numerous bacterial species. They use them to regulate the ... Lee, S.J.; Park, S.Y.; Lee, J.J.; Yum, D.Y.; Koo, B.T.; Lee, J.K. (2002). "Genes encoding the N-acyl homoserine lactone- ...

*Threonine

... aspartokinase β-aspartate semialdehyde dehydrogenase homoserine dehydrogenase homoserine kinase threonine synthase. Threonine ... Homoserine undergoes O-phosphorylation; this phosphate ester undergoes hydrolysis concomitant with relocation of the OH group. ... In plants and microorganisms, threonine is synthesized from aspartic acid via α-aspartyl-semialdehyde and homoserine. ...

*O-acetylhomoserine aminocarboxypropyltransferase

Other names in common use include O-acetyl-L-homoserine acetate-lyase (adding methanethiol), O-acetyl-L-homoserine ... Kuramitsu S, Iwama T (2001). "Cloning and overexpression of the oah1 gene encoding O-acetyl-L-homoserine sulfhydrylase of ... Yamagata S (1989). "Roles of O-acetyl-L-homoserine sulfhydrylases in micro-organisms". Biochimie. 71 (11-12): 1125-43. doi: ... The systematic name of this enzyme class is O-acetyl-L-homoserine:methanethiol 3-amino-3-carboxypropyltransferase. ...

*Morpheein

Ogilvie, JW; Vickers, LP; Clark, RB; Jones, MM (1975). "Aspartokinase I-homoserine dehydrogenase I of Escherichia coli K12 ( ...

*Canaline

As homoserine, its carbon skeleton also finds an important use. Rosenthal, Gerald A. (1982). Plant non-protein amino and imino ... L-Canaline can by reductively cleaved to L-homoserine, a non-protein amino acid of great importance in the formation of a host ...

*Pantoea

Isolated from Tropical Fresh Water Exhibiting N-Acyl Homoserine Lactone Production". The Scientific World Journal. 2014 (2014 ...

*Stewart's wilt

Isolated from Tropical Fresh Water Exhibiting N-Acyl Homoserine Lactone Production". Hindawi. 2014 (2014): 1. doi:10.1155/2014/ ...

*Cystathionine gamma-synthase

... homoserine transsuccinylase, 4-O-succinyl-L-homoserine:L-cysteine, and S-(3-amino-3-carboxypropyl)transferase. This enzyme ... The systematic name of this enzyme class is O4-succinyl-L-homoserine:L-cysteine S-(3-amino-3-carboxypropyl)transferase. Other ... Wiebers JL, Garner HR (1967). "Acyl derivatives of homoserine as substrates for homocysteine synthesis in Neurospora crassa, ... Flavin M, Slaughter C (1967). "Enzymatic synthesis of homocysteine or methionine directly from O-succinyl-homoserine". Biochim ...

*Nocardioides kongjuensis

... has the ability to degrade N-Acyl homoserine lactone. Parte, A.C. "Nocardioides". www.bacterio.net. " ...

*Amino acid synthesis

This reaction occurs at a key branch point in the pathway, with the substrate homoserine serving as the precursor for the ... High levels of threonine result in low levels of homoserine synthesis. The synthesis of aspartate kinase (AK), which catalyzes ... The biosynthesis of threonine is regulated via allosteric regulation of its precursor, homoserine, by structurally altering the ... There are two bifunctional aspartokinase/homoserine dehydrogenases, ThrA and MetL, in addition to a monofunctional ...

*Lactonase

... hydrolyzes the ester bond of the homoserine lactone ring of acylated homoserine lactones. In hydrolysing the lactone ... Lactonase (also acyl-homoserine lactonase) is a metalloenzyme, produced by certain species of bacteria, which targets and ... Dong Y. H.; Gusti A. R.; Zhang Q.; Xu J. L.; Zhang, L. H. (2002). "Identification of quorum-quenching N-acyl homoserine ... Dong Y. H.; Gusti A. R.; Zhang Q.; Xu J. L.; Zhang, L. H. (2002). "Identification of quorum-quenching N-acyl homoserine ...

*Quorum sensing

This mechanism can be understood by looking at the effects of N-acyl Homoserine Lactone (AHL) which is one of the QS-signalling ... 2012) Acyl homoserine lactone-based quorum sensing in a methanogenic archaeon. The ISME Journal. advanced online publication ... The latter disrupts the synthesis of a class of signalling molecules known as N-acyl homoserine lactones (AHLs) by blocking the ... Gram-negative bacteria produce N-acyl homoserine lactones (AHL) as their signaling molecule. Usually AHLs do not need ...

*Variovorax paradoxus

Strains of V. paradoxus have also been identified that can degrade N-acyl homoserine-lactones (AHL), microbial signalling ... Leadbetter, Jared R.; Greenberg, E. P. (2000-12-15). "Metabolism of Acyl-Homoserine Lactone Quorum-Sensing Signals by ...

*Muricauda olearia

... a novel marine-derived N-acyl homoserine lactonase from Muricauda olearia". Applied and Environmental Microbiology. 81 (2): 774 ...

*Interspecies quorum sensing

The first pathway uses a typical AI-1 homoserine lactone signaling molecule. However the bacteria were also found to recognize ...
PubMed comprises more than 30 million citations for biomedical literature from MEDLINE, life science journals, and online books. Citations may include links to full-text content from PubMed Central and publisher web sites.
Quorum sensing is a process of bacterial cell-to-cell communication involving the production and detection of extracellular signaling molecules called autoinducers. Recently, it has been proposed that autoinducer-2 (AI-2), a furanosyl borate diester derived from the recycling of S-adenosyl-homocysteine (SAH) to homocysteine, serves as a universal signal for interspecies communication. In this study, 138 completed genomes were examined for the genes involved in the synthesis and detection of AI-2. Except for some symbionts and parasites, all organisms have a pathway to recycle SAH, either using a two-step enzymatic conversion by the Pfs and LuxS enzymes or a one-step conversion using SAH-hydrolase (SahH). 51 organisms including most Gamma-, Beta-, and Epsilonproteobacteria, and Firmicutes possess the Pfs-LuxS pathway, while Archaea, Eukarya, Alphaproteobacteria, Actinobacteria and Cyanobacteria prefer the SahH pathway. In all 138 organisms, only the three Vibrio strains had strong, bidirectional matches
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β-Lactone natural products and derivatives inactivate homoserine transacetylase, a target for antimicrobial agents.. Japanese Journal of Antibiotics Journal of Antibiotics. 64:483-487. 2011 ...
4GO1: Structural Basis for Phosphorylated Autoinducer-2 Modulation of the Oligomerization State of the Global Transcription Regulator LsrR from Escherichia coli
4GO1: Structural Basis for Phosphorylated Autoinducer-2 Modulation of the Oligomerization State of the Global Transcription Regulator LsrR from Escherichia coli
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Salmonella typhi utilize inter and intra species communication via the process of cell-cell communication, which use to regulate population density with small, diffusible signaling molecules as communication intermediary called Autoinducers-2 (AI-2). Lsrk is the kinase phosphorylate AI-2, be capable to simulate the lsr operon. On the other hand, a solved structure of LsrK from Salmonella typhi is not available on Protein Data Bank. For that reason, we modelled and validated LsrK through online servers. Secondary structural insights were discussed. These findings provide new knowledge to molecular understanding of Autoinducer-2 kinase within Salmonella typhi.. ...
The term `quorum sensing (QS) is used to define a population density based communication mechanism which uses chemical signal molecules called autoinducers to trigger unique and varied changes in gene expression. Although several communication methods have been identified in bacteria that are unique to a particular species, one type of signal molecule, autoinducer-2 (AI-2) is linked to interspecies communication, indicating its potential as a universal signal for cueing a QS response among multiple bacterial types. In E. coli, AI-2 acts as an effector by binding to the QS repressor LsrR. As a result, LsrR unbinds and relieves repression of the lsr regulon, stimulating a subsequent QS gene expression cascade. In this dissertation, LsrR structure and in vitro binding activity are examined. Genomic binding and DNA microarray analyses are conducted and three novel sites putatively regulated by LsrR, yegE-udk, mppA and yihF, are revealed. Two cAMP receptor protein (CRP) binding locations in ...
Looking for online definition of homoserine dehydratase in the Medical Dictionary? homoserine dehydratase explanation free. What is homoserine dehydratase? Meaning of homoserine dehydratase medical term. What does homoserine dehydratase mean?
definition of HBHL, what does HBHL mean?, meaning of HBHL, Hydroxybutanoyl Homoserine Lactone, HBHL stands for Hydroxybutanoyl Homoserine Lactone
When modelling the population of repressilator-containing bacteria in BSim, we used many of the same features as the model outlined in [2]. The repressilators themselves are modelled as a system of 7 ODEs; 3 ODEs representing the 3 different mRNA levels, 3 ODEs for the 3 corresponding proteins, and one ODE for the internal level of autoinducer. These are in turn coupled to an external spatially varying chemical field via the autoinducer term, which incorporates physically correct diffusion and degradation characteristics. For the modelling of the autoinducer behaviour, we made the assumption that the autoinducer in question was AHL as this is a common quorum signalling molecule. The parameters for diffusion (in space and through the cell wall) and decay were then set accordingly. The parameter governing the ratio between mRNA and protein degradation was chosen from a random distribution as in the first part of [2]. ...
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Autoinducer-2 (AI-2), a furanosyl borate diester, is a member of a family of signaling molecules used in quorum sensing. AI-2 is one of only a few known biomolecules incorporating boron. First identified in the marine bacterium Vibrio harveyi, AI-2 is produced and recognized by many Gram-negative and Gram-positive bacteria. AI-2 arises by the reaction of 1-deoxy-3-dehydro-D-ribulose, which is produced enzymatically, with boric acid and is recognized by the two-component sensor kinase LuxPQ in Vibrionaceae. AI-2 is actively transported by the Lsr ABC-type transporter into the cell in Enterobacteriaceae and few other bacterial taxa (Pasteurella, Photorhabdus, Haemophilus, Bacillus), where it is phosphorylated by LsrK . Then, Phospho-AI-2 binds the transcriptional repressor protein, LsrR, which subsequently is released from the promoter/operator region of the lsr operon - and transcription of the lsr genes is initiated. AI-2 signalling is also regulated by glucose and cAMP/CRP via the lsr operon. ...
In this paper, we investigated the intra-species bacterial quorum sensing at the single cell level using a double droplet trapping system. Escherichia coli transformed to express the quorum sensing receptor protein, LasR, were encapsulated in microdroplets that were positioned adjacent to microdroplets containing the autoinducer, N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL). Functional activation of the LasR protein by diffusion of the OdDHL across the droplet interface was measured by monitoring the expression of green fluorescent protein (GFP) from a LasR-dependent promoter. A threshold concentration of OdDHL was found to induce production of quorum-sensing associated GFP by E. coli. Additionally, we demonstrated that LasR-dependent activation of GFP expression was also initiated when the adjacent droplets contained single E. coli transformed with the OdDHL synthase gene, LasI, representing a simple quorum sensing circuit between two droplets.
In this paper, we investigated the intra-species bacterial quorum sensing at the single cell level using a double droplet trapping system. Escherichia coli transformed to express the quorum sensing receptor protein, LasR, were encapsulated in microdroplets that were positioned adjacent to microdroplets containing the autoinducer, N-(3-oxododecanoyl)-L-homoserine lactone (OdDHL). Functional activation of the LasR protein by diffusion of the OdDHL across the droplet interface was measured by monitoring the expression of green fluorescent protein (GFP) from a LasR-dependent promoter. A threshold concentration of OdDHL was found to induce production of quorum-sensing associated GFP by E. coli. Additionally, we demonstrated that LasR-dependent activation of GFP expression was also initiated when the adjacent droplets contained single E. coli transformed with the OdDHL synthase gene, LasI, representing a simple quorum sensing circuit between two droplets.
Quorum sensing (QS) or cell-to-cell communication is a process by which bacteria produce and detect signal molecules and thereby coordinate their behavior in a cell-density dependent manner. Two main QS systems can be distinguished: the acylhomoserine lactone (AHL) and the autoinducer-2 (AI-2). The sequenced genome of the marine bioluminescent Shewanella woodyi MS32 contains genes coding for these two main QS systems. This work aims at identifying the QS communication systems present in this bacterium and understanding its role in luminescence production and biofilm formation. The objective is also to find molecules that interfere with QS processes to inhibit adhesion and biofilm formation ...
For a full list of publications. Selected recent publications. Yifat Glucksam-Galnoy, Roy Sananes, Nava Silberstein, Pnina Krief, Vladimir V. Kravchenko, Michael M. Meijler and Tsaffrir Zor, The bacterial quorum-sensing signal molecule N-3-oxo-dodecanoyl-L-homoserine lactone reciprocally modulates pro- and anti-inflammatory cytokines in activated macrophages, Journal of Immunology, 2013, 191, 337-344. (pdf). Dorit Avni, Yifat Glucksam and Tsaffrir Zor , The Phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 modulates cytokine expression in mouse macrophages via p50 nuclear factor kappa B inhibition, in a PI3K-independent mechanism, Biochemical Pharmacology, 2012, 83, 106-114. (pdf). Meir Goldsmith, Ala Daka, Nadia F. Lamour, Roi Mashiach, Yifat Glucksam, Charles E. Chalfant, Michael M. Meijler and Tsaffrir Zor, A ceramide analog inhibits cPLA2 activity and consequent PGE2 formation in LPS-stimulated macrophages, Immunology Letters, 2011, 135, 136-143. ( pdf ). Dorit Avni , Orna Ernst , Amir ...
The marine bacterium Vibrio harveyi controls its bioluminescence by a process known as quorum sensing. In this process, autoinducer molecules are detected by membrane-bound sensor kinase/response regulator proteins (LuxN and LuxQ) that relay a signal via a series of protein phosphorylation reactions to another response regulator protein, LuxO. Phosphorylated LuxO indirectly represses the expression of the proteins responsible for bioluminescence. Integral to this quorum sensing process is the function of the phosphotransferase protein, LuxU.
Autoinducers are signaling molecules that are produced in response to changes in cell-population density. As the density of quorum sensing bacterial cells increases so does the concentration of the autoinducer. Detection of signal molecules by bacteria acts as stimulation which leads to altered gene expression once the minimal threshold is reached. Quorum sensing is a phenomenon that allows both Gram-negative and Gram-positive bacteria to sense one another and to regulate a wide variety of physiological activities. Such activities include symbiosis, virulence, motility, antibiotic production, and biofilm formation. Autoinducers come in a number of different forms depending on the species, but the effect that they have is similar in many cases. Autoinducers allow bacteria to communicate both within and between different species. This communication alters gene expression and allows bacteria to mount coordinated responses to their environments, in a manner that is comparable to behavior and ...
At low cell density, in absence of AI-2 (autoinducer 2), LuxQ has a kinase activity and autophosphorylates on a histidine residue. The phosphoryl group is then transferred to an aspartate residue in the response regulator domain. The phosphoryl group is transferred to LuxU, and ultimately to LuxO. At high cell density, in the presence of AI-2, the kinase activity is inactivated, and the response regulator domain has a phosphatase activity.
The Golm Metabolome Database (GMD) facilitates the search for and dissemination of mass spectra from biologically active metabolites quantified using GC-MS.
The Golm Metabolome Database (GMD) facilitates the search for and dissemination of mass spectra from biologically active metabolites quantified using GC-MS.
Even though bacteria live their lives as single-celled entities, they still need to keep up to date with what their neighbors, friendly and otherwise, are doing. In a process called quorum sensing, Vibrio harveyi monitors its surroundings via two protein phosphorylation pathways that produce and detect autoinducers 1 and 2 (AI-1 and AI-2). The first is restricted to V. harveyi and a close relative, whereas the second is found in a wide variety of both Gram-negative and Gram-positive species. Mok et al. identify a number of target genes whose expression is regulated by AI-2. From an analysis of the responses of these genes to combinations of AI-1 and AI-2, they propose that this pair of pathways may serve as a coincidence detector, primarily designed to signal the presence of both inducers and, in essence, acting as an AND gate. - GJC. EMBO J.22, 870 (2003).. ...
Quorum sensing is a form of cell-to-cell communication by which bacteria communicate by secreting signaling molecules called autoinducers that help regulate gene expression.
Buy Characterization of S-Ribosylhomocysteinase (Luxs) by Jinge Zhu for $249.99 at Mighty Ape NZ. S-Ribosylhomocysteinase (LuxS) catalyzes the cleavage of the thioether bond in S-ribosylhomocysteine to produce L- homocysteine and 4,5-dihydroxy-2,3-...
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Accepted name: acyl-homoserine-lactone acylase. Reaction: an N-acyl-L-homoserine lactone + H2O = L-homoserine lactone + a carboxylate. Other name(s): acyl-homoserine lactone acylase; AHL-acylase; AiiD; N-acyl-homoserine lactone acylase; PA2385 protein; quorum-quenching AHL acylase; quorum-quenching enzyme; PvdQ; QuiP. Systematic name: N-acyl-L-homoserine-lactone amidohydrolase. Comments: Acyl-homoserine lactones (AHLs) are produced by a number of bacterial species and are used by them to regulate the expression of virulence genes in a process known as quorum-sensing. Each bacterial cell has a basal level of AHL and, once the population density reaches a critical level, it triggers AHL-signalling which, in turn, initiates the expression of particular virulence genes. Plants or animals capable of degrading AHLs would have a therapeutic advantage in avoiding bacterial infection as they could prevent AHL-signalling and the expression of virulence genes in quorum-sensing bacteria. This ...
PubMed Central Canada (PMC Canada) provides free access to a stable and permanent online digital archive of full-text, peer-reviewed health and life sciences research publications. It builds on PubMed Central (PMC), the U.S. National Institutes of Health (NIH) free digital archive of biomedical and life sciences journal literature and is a member of the broader PMC International (PMCI) network of e-repositories.
Most studies of biofilms have focused on single species and on genes that control or are regulated by life on a surface. As more information is uncovered by studies of pure cultures, these data can be applied towards understanding the roles of specific genes in multispecies interactions. This chapter focuses mostly on multi-species interactions among oral bacteria in biofilms: a few single-species biofilms are featured to discuss responses to environmental signals, including signals generated by the occupants within the biofilm. Signals involved in cell-to-cell communication among biofilm cells include acyl homoserine lactones, oligopeptides, and autoinducer-2 (AI-2). Importantly, an optimal concentration of 4,5-dihydroxy-2,3-pentanedione (DPD) was critical for maximal biofilm development. One site where natural multispecies biofilms are unusually accessible is the tooth surface in the human oral cavity. We use a retrievable enamel chip model system that permits us to place three pieces of enamel side
A number of bacteria use a class of chemical compounds called acyl-homoserine lactones (AHLs) as quorum sensing (QS) signals to coordinate their behavior at the population level, including pathogens...
Many bacteria have multiple QS systems, as seen with P. aeruginosa. Although autoinducer are usually specific to their receptor, there is sometimes nonspecific signaling or cross-talk between these systems. For example, there is interaction in cystic fibrosis patients between P. aeruginosa and B. cepacia,cite,#Riedel,/cite,. B. cepacia can recognize the HSL signals produced by P. aeruginosa to activate its cep QS system, but P. aeruginosa cannot recognize any of B. cepacias signals. This is important for understanding cystic fibrosis development since B. cepacia colonizes only after P. aeruginosa is already established. This suggests that quorum sensing is vital for the development of multispecies communities. Multispecies communication can also be specific. luxS, used to synthesize autoinducer-2 (AI-2), has been found in over 55 species of bacteria,cite,#Keersmaecker,/cite, and has been found to regulate biofilm development ...
Many bacteria have multiple QS systems, as seen with P. aeruginosa. Although autoinducer are usually specific to their receptor, there is sometimes nonspecific signaling or cross-talk between these systems. For example, there is interaction in cystic fibrosis patients between P. aeruginosa and B. cepacia,cite,#Riedel,/cite,. B. cepacia can recognize the HSL signals produced by P. aeruginosa to activate its cep QS system, but P. aeruginosa cannot recognize any of B. cepacias signals. This is important for understanding cystic fibrosis development since B. cepacia colonizes only after P. aeruginosa is already established. This suggests that quorum sensing is vital for the development of multispecies communities. Multispecies communication can also be specific. luxS, used to synthesize autoinducer-2 (AI-2), has been found in over 55 species of bacteria,cite,#Keersmaecker,/cite, and has been found to regulate biofilm development ...
Highly virulent enterococcal strains have a pathogenicity island within their genome that encodes, among other traits, a cytolytic toxin that uses a quorum-sensing mechanism to affect autoinduction. Coburn et al. (see the Perspective by Garsin) show that the bacterium actively secretes two components, an autoinducer and an anti-autoinducer. In the absence of target cells, these two interact and prevent the autoinducer from feeding back to induce high-level expression of the cytolysin. In the presence of the target cell, however, the anti-autoinducer binds to the target cell and allows the autoinducer to accumulate to the threshold level required for quorum induction of the cytolysin operon. The anti-autoinducer is itself a toxin component and effectively tags the target for destruction. P. S. Coburn, C. M. Pillar, B. D. Jett, W. Haas, M. S. Gilmore, Enterococcus faecalis senses target cells and in response expresses cytolysin. Science 306, 2270-2272 (2004). [Abstract] [Full Text]. D. A. Garsin, ...
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You are viewing an interactive 3D depiction of the molecule N-(2,2-dimethylpropyl)-N-(1-methylcyclobutyl)hydroxylamine (C10H22NO+) from the PQR.
Effect of growth phase (A) and medium (B) on AI-2 production in representative species of the genus Shewanella. (A) Comparison between a Shewanella species with
Diets, Growth, Sensitivity, Corn, Methionine, Sulfur, Diet, Homoserine, Eye, Eyes, Orientation, Retinal, Binocular, Discrimination, Population, Acidosis, Acids, Amino Acids, Arginine, Betaine
The Lyme disease spirochete, Borrelia burgdorferi, controls protein expression patterns during its tick-mammal infection cycle. Earlier studies demonstrated that B. burgdorferi synthesizes 4,5-dihydroxy-2,3-pentanedione (autoinducer-2 [AI-2]) and responds to AI-2 by measurably changing production of several infection-associated proteins. luxS mutants, which are unable to produce AI-2, exhibit altered production of several proteins. B. burgdorferi cannot utilize the other product of LuxS, homocysteine, indicating that phenotypes of luxS mutants are not due to the absence of that molecule. Although a previous study found that a luxS mutant was capable of infecting mice, a critical caveat to those results is that bacterial loads were not quantified. To more precisely determine whether LuxS serves a role in mammalian infection, mice were simultaneously inoculated with congenic wild-type and luxS strains, and bacterial numbers were assessed using quantitative PCR. The wild-type bacteria substantially
In recent years it has become clear that the production of N-acyl homoserine lactones (N-AHLs) is widespread in Gram-negative bacteria. These molecules act as diffusible chemical communication signals (bacterial pheromones) which regulate diverse physiological processes including bioluminescence, antibiotic production, piasmid conjugal transfer and synthesis of exoenzyme virulence factors in plant and animal pathogens. The paradigm for N-AHL production is in the bioluminescence (lux) phenotype of Photobacterium fischeri (formerly classified as Vibrio fischeri) where the signalling molecule N-(3-oxohexanoyl)-L-homoserine lactone (OHHL) is synthesized by the action of the Luxl protein. OHHL is thought to bind to the LuxR protein, allowing it to act as a positive transcriptional activator in an autoinduction process that physiologically couples cell density (and growth phase) to the expression of the bioluminescence genes. Based on the growing information on Luxl and LuxR homologues in other ...
Homoserine is a more reactive variant of the amino acid serine. In this variant, the hydroxyl side chain contains an additional CH2 group which brings the hydroxyl group closer to its own carboxyl group, allowing it to chemically react to form a five-membered ring. This occurs at the point that amino acids normally join to their neighbours in a peptide bond. Homoserine is therefore unsuitable for forming proteins and has been eliminated from the repertoire of amino acids used by living things. Homoserine is the final product on the C-terminal end of the N-terminal fragment following a cyanogen bromide cleavage. (wikipedia ...
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Janthinobacteria commonly form biofilms on eukaryotic hosts and are known to synthesize antibacterial and antifungal compounds. Janthinobacterium sp. HH01 was recently isolated from an aquatic environment and its genome sequence was established. The genome consists of a single chromosome and reveals a size of 7.10 Mb, being the largest janthinobacterial genome so far known. Approximately 80% of the 5,980 coding sequences (CDSs) present in the HH01 genome could be assigned putative functions. The genome encodes a wealth of secretory functions and several large clusters for polyketide biosynthesis. HH01 also encodes a remarkable number of proteins involved in resistance to drugs or heavy metals. Interestingly, the genome of HH01 apparently lacks the N-acylhomoserine lactone (AHL)-dependent signaling system and the AI-2-dependent quorum sensing regulatory circuit. Instead it encodes a homologue of the Legionella- and Vibrio-like autoinducer (lqsA/cqsA) synthase gene which we designated jqsA. The ...
AM: The presumption that we cannot communicate across species comes from the worldview that says there is this human world and then there is this animal world or the environment outside of us. All kinds of cultures throughout time have included myths and stories about people communicating across boundaries of species. It doesnt have to be like some woo-woo New Age thing. It is just part of being a living creature on this planet that species are interacting with each other across species boundaries in all kinds of ways.. It doesnt mean we are reading each others thoughts or completely understand what is going on in each others minds. The birds outside my window are not making noise because there is a huge construction truck making a whole lot of noise instead. That is interspecies communication or interruption of interspecies communication. We are all in this thing together. I am really interested in the scientists that are taking that to another level and saying beyond metaphor what is ...
Bacteria coordinate cell density dependent behaviors by communicating through chemical intermediaries in a process called quorum sensing. In a bacterial culture, individual cells will constitutively produce signal molecules, termed autoinducers, and export them into the environment. When the concentration of autoinducers reaches a threshold, the cells sense that they are in a specific situation, which requires the upregulation of certain genes. This upregulation causes the bacteria to produce proteins that allow them to take part in a coordinated population-wide behavior. In bacteria that are naturally competent, or capable of importing DNA from the environment, the expression of competence genes is often regulated by quorum sensing. Recent evidence has shown that the archaean Haloferax volcanii is naturally competent, which leads to the hypothesis that H.volcanii may use quorum sensing as a regulatory mechanism as well. In the domain Archaea, quorum sensing is a phenomenon that has received very
ID F6B967_DESCC Unreviewed; 305 AA. AC F6B967; DT 27-JUL-2011, integrated into UniProtKB/TrEMBL. DT 27-JUL-2011, sequence version 1. DT 27-SEP-2017, entry version 40. DE RecName: Full=Homoserine kinase {ECO:0000256,HAMAP-Rule:MF_00384, ECO:0000256,SAAS:SAAS00649262}; DE Short=HK {ECO:0000256,HAMAP-Rule:MF_00384}; DE Short=HSK {ECO:0000256,HAMAP-Rule:MF_00384}; DE EC=2.7.1.39 {ECO:0000256,HAMAP-Rule:MF_00384, ECO:0000256,SAAS:SAAS00836515}; GN Name=thrB {ECO:0000256,HAMAP-Rule:MF_00384}; GN OrderedLocusNames=Desca_2000 {ECO:0000313,EMBL:AEF94839.1}; OS Desulfotomaculum nigrificans (strain DSM 14880 / VKM B-2319 / OS CO-1-SRB) (Desulfotomaculum carboxydivorans). OC Bacteria; Firmicutes; Clostridia; Clostridiales; Peptococcaceae; OC Desulfotomaculum. OX NCBI_TaxID=868595 {ECO:0000313,EMBL:AEF94839.1, ECO:0000313,Proteomes:UP000009226}; RN [1] {ECO:0000313,EMBL:AEF94839.1, ECO:0000313,Proteomes:UP000009226} RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA]. RC STRAIN=DSM 14880 / VKM B-2319 / CO-1-SRB ...
He appears to fancy himself as a humourist. When another parrot hung upside down from its perch, he commented: "You got to put this bird on the camera." Dr Goodall says Nkisis verbal fireworks are an "outstanding example of interspecies communication". In an experiment, the bird and his owner were put in separate rooms and filmed as the artist opened random envelopes containing picture cards. Analysis showed the parrot had used appropriate keywords three times more often than would be likely by chance. Captives frustrations This was despite the researchers discounting responses like "What ya doing on the phone?" when Nkisi saw a card of a man with a telephone, and "Can I give you a hug?" with one of a couple embracing. Professor Donald Broom, of the University of Cambridges School of Veterinary Medicine, said: "The more we look at the cognitive abilities of animals, the more advanced they appear, and the biggest leap of all has been with parrots." Alison Hales, of the World Parrot Trust, ...
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Bacterial cells often form sessile biofilms that are up to 1,000 times more resistant to antimicrobial agents than free-living cells. Meanwhile, bacteria produce a small subpopulation of slow-growing or non-growing persister cells that exhibit high tolerance to antibiotics. Both biofilms and persister cells play important roles in the recalcitrance of chronic infections. Recent studies have shown that bacterial cell-to-cell communication, named quorum sensing (QS), is involved in the biofilm and persister formation. In this study, we investigated the effects of quorum sensing signals N-(3-oxododecanoyl)-homoserine lactone (3-oxo-C12-HSL) and N-butyryl homoserine lactone (C4-HSL) on isolated Pseudomonas aeruginosa PAO1 and PDO300 persister cells. Interestingly, 3-oxo-C12-HSL was found to increase antibiotic susceptibility of isolated P. aeruginosa PAO1 and PDO300 persister cells to ciprofloxacin in a dose-dependent manner, although such synergistic effect was not observed with ofloxacin, tobramycin,
Communication between bacterial cells is crucial for the coordination of diverse cellular processes that facilitate environmental adaptation and, in the case of pathogenic species, virulence. This is achieved by the secretion and detection of small signaling molecules called autoinducers, a process termed quorum sensing. To date, the only signaling molecule recognized by both Gram-positive and Gram-negative bacteria is autoinducer 2 (AI-2), synthesized by the metabolic enzyme LuxS (S-ribosylhomocysteine lyase) as a by-product of the activated methyl cycle. Homologues of LuxS are ubiquitous in bacteria, suggesting a key role in interspecies, as well as intraspecies, communication. Gram-negative bacteria sense and respond to AI-2 via the Lsr ABC transporter system or by the LuxP/LuxQ phosphorelay system. However, homologues of these systems are absent from Gram-positive bacteria and the AI-2 receptor is unknown. Here we show that in the major human pathogen Streptococcus pneumoniae, sensing of ...
Sigma-Aldrich offers abstracts and full-text articles by [Danielle M Stacy, Michael A Welsh, Philip N Rather, Helen E Blackwell].
We report the draft genome sequence of Staphylococcus sp. strain AL1, which degrades quorum-sensing molecules (namely, N-acyl homoserine lactones). To the best of our knowledge, this is the first documentation that reports the whole genome sequence a
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Involved in the synthesis of autoinducer 2 (AI-2) which is secreted by bacteria and is used to communicate both the cell density and the metabolic potential of the environment. The regulation of gene expression in response to changes in cell density is called quorum sensing. Catalyzes the transformation of S-ribosylhomocysteine (RHC) to homocysteine (HC) and 4,5-dihydroxy-2,3-pentadione (DPD).
To investigate the possibility of using commensal bacteria as signal mediators for inhibiting the disease cholera (caused by infection with the marine bacterium V. cholerae), we stably transformed commensal bacteria to express the autoinducer molecule CAI-1 (shown previously to prevent virulence when present with another signaling molecule, AI-2 at high concentrations) and determined the effect on V. cholerae virulence gene expression and infectivity in an infant mouse model. We found that pretreatment of mice for 8 hours with commensal bacteria engineered to express CAI-1 (Nissle-cqsA) greatly increased the mices survival (92%) from ingestion of V. cholerae. Pretreatment with Nissle-cqsA for only 4 hours increased survival by 77%, while ingesting Nissle-cqsA at the same time as V. cholerae increased survival rates by 27%. Immuno-staining revealed an 80% reduction in cholera toxin binding to the intestines of mice pretreated for 8 hours with Nissle-cqsA. Further, the numbers of V. cholerae in ...
Quorum sensing (QS) is a regulatory system that allows bacteria to share information about cell density and adjust gene expression accordingly. All QS bacteria produce and release chemical signal molecules called autoinducers (AIs) that increase in concentration as a function of cell density. The most commonly studied AIs belong to one of the following three categories: acylated homoserine lactones, also referred to as AI-1, used by Gram-negative bacteria; peptide signals, used by Gram-positive bacteria; and AI-2, used by both Gram-negative and Gram-positive bacteria. QS can be divided into at least 4 steps: production of AIs by the bacterial cell; release of AIs, either actively or passively, into the surrounding environment; recognition of AIs by specific receptors; and leading to changes in gene regulation once they exceed a threshold concentration. The processes controlled by QS include virulence, competence, conjugation, antibiotic production, motility, sporulation, and biofilm formation ...
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Ethology. Interspecies communication. Animal communication. Animal cognition. Emotion in animals. Animal culture. Animal sexual behaviour. A range of animal
You could grow some bacteria in a food source that contains only heavy isotope of nitrogen - N-15. After many generations, the DNA should only contain the heavy isotope of nitrogen. Some bacteria can be transferred to another food source containing the normal lighter isotope of nitrogen - N-14. The DNA can be extracted from the bacteria and separated e.g. centrifuged. The more dense, heavier molecules (N-15) will stay at the bottom. it could be centrifuged bu mixing the DNA sample with cocentrated sugar solution then placing the mixture of DNA and sugar solution into test tubes and spinning them at high ...
U.S. researchers say they have discovered a novel quorum-sensing pathway in Saccharomyces cerevisiae, also known as bakers yeast.
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#885883 헥스 색상 코드의 색상 스킴, 페인트, 팔레트, 콤비네이션, 그라디언트 및 색상 스페이스 변환.
مخططات وطلاءات، ونطاقات الألوان، والتركيبات، والتدرجات، والفضاء اللوني، والتحويلات لألوان ‎#0001e8 الست عشرية.
مخططات وطلاءات، ونطاقات الألوان، والتركيبات، والتدرجات، والفضاء اللوني، والتحويلات لألوان ‎#0000e2 الست عشرية.
#0003db 헥스 색상 코드의 색상 스킴, 페인트, 팔레트, 콤비네이션, 그라디언트 및 색상 스페이스 변환.
Multidrug resistant (MDR) strains of Pseudomonas aeruginosa are a growing threat to humans. P. aeruginosa coordinates a wide variety of behavior through the LasI/LasR quorum sensing pathway. This includes behavior that is virulent to host cells. Acyl homoserine lactones (AHLs) are autoinducers of the LasI/LasR pathway. After synthesis by LasI, a LuxI-type acyl homoserine lactone (AHL) synthase, AHLs are secreted to the extracellular space. They re-enter neighboring bacteria and activate the quorum sensing receptor LasR, the major transcriptional regulator for the pathway. By focusing on LasI inhibition, our research goal is to develop an antivirulence strategy against MDR strains of P. aeruginosa based on disrupting LasI/LasR quorum sensing pathway using small molecule inhibitors of LasI. This is expected to reduce AHL synthesis, induction of the LasI/LasR pathway, and subsequent virulent behavior. By simulating LuxI-type AHL synthases and docking them with AHL-like inhibitor analogs, we identify a
TY - JOUR. T1 - Catalysts and supports for conversion of lactic acid to acrylic acid and 2,3-pentanedione. AU - Gunter,Garry C.. AU - Langford,Robert H.. AU - Jackson,James E.. AU - Miller,Dennis J.. PY - 1995/3. Y1 - 1995/3. N2 - The catalytic conversion of lactic acid over various sodium salt catalysts and support materials has been carried out to identify potential catalyst/support combinations for 2,3-pentanedione and acrylic acid production. Low surface area, pure silica is the best support for suppressing undesirable side reactions to acetaldehyde and propanoic acid, which are favored over high surface area (microporous) or surface acidic materials. The best catalysts for 2,3-pentanedione and acrylic acid formation are the sodium salts of group IV and group V oxides, with sodium arsenate giving a 2,3-pentanedione yield of 25% and combined selectivity to acrylic acid and 2,3-pentanedione of 83% at 300 °C and 0.5 MPa total pressure.. AB - The catalytic conversion of lactic acid over various ...
The most well studied of the more recently identified quorum-sensing molecules in fungi are small primary alcohols, thus chemically different from the acyl-homoserine lactones and modified peptides preferred by bacteria. These primary alcohols include farnesol and tyrosol in Candida albicans, and phenylethanol and tryptophol in Saccharomyces cerevisiae. This chapter talks about molecules after a review of the mating pheromones and a more detailed discussion of the primary alcohol quorum-sensing molecules. In S. cerevisiae, members of the same mitogen-activated protein kinase (MAPK) signaling cascade are involved in both pheromone response and agar invasion in haploid cells, and in Ustilago maydis, the loci expressed in response to mating pheromone contain genes involved in filamentous growth and pathogenicity. This coordination between mating and morphogenesis in fungi is analogous to the connection between competence and virulence in Streptococcus pneumoniae and other gram-positive bacteria, which is
Bacteria can coordinate and synchronize activities through a cell density-dependent regulatory mechanism called quorum sensing (QS). Bacteria can measure their population by the synthesis, secretion, and perception of QS signal molecules to regulate specific gene expression when the population reaches a critical threshold. QS participates in various microbial processes such as marine organism bioluminescence, bacterial biofilm formation, and virulence factor expression. The use of QS systems mediated by N-acyl-homoserine lactones and autoinducer-2 has been recently recognized as a promising regulatory approach in environmental science and technology that can intrinsically promote the profound comprehension of wastewater treatment from a microbiology perspective ...
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Quorum sensing is a bacterial communication mechanism that controls genes, enabling bacteria to live as communities, such as biofilms. Homoserine lactone (HSL) molecules function as quorum-sensing signals for Gram-negative bacteria. Plants also produce previously unidentified compounds that affect quorum sensing. We identified rosmarinic acid as a plant-derived compound that functioned as an HSL mimic. In vitro assays showed that rosmarinic acid bound to the quorum-sensing regulator RhlR of Pseudomonas aeruginosa PAO1 and competed with the bacterial ligand N-butanoyl-homoserine lactone (C4-HSL). Furthermore, rosmarinic acid stimulated a greater increase in RhlR-mediated transcription in vitro than that of C4-HSL. In P. aeruginosa, rosmarinic acid induced quorum sensing-dependent gene expression and increased biofilm formation and the production of the virulence factors pyocyanin and elastase. Because P. aeruginosa PAO1 infection induces rosmarinic acid secretion from plant roots, our results ...
Burkholderia pseudomallei is the causative agent of melioidosis, a fatal human tropical disease. The non-specific DNA-binding protein DpsA plays a key role in protecting B. pseudomallei from oxidative stress mediated, for example, by organic hydroperoxides. The regulation of dpsA expression is poorly understood but one possibility is that it is regulated in a cell population density-dependent manner via N-acylhomoserine lactone (AHL)-dependent quorum sensing (QS) since a lux-box motif has been located within the dpsA promoter region. Using liquid chromatography and tandem mass spectrometry, it was first established that B. pseudomallei strain PP844 synthesizes AHLs. These were identified as N-octanoylhomoserine lactone (C8-HSL), N-(3-oxooctanoyl)homoserine lactone (3-oxo-C8-HSL), N-(3-hydroxyoctanoyl)-homoserine lactone (3-hydroxy-C8-HSL), N-decanoylhomoserine lactone (C10-HSL), N-(3-hydroxydecanoyl) homoserine lactone (3-hydroxy-C10-HSL) and N-(3-hydroxydodecanoyl)homoserine lactone (3-hydroxy-C12-HSL)
Quorum-quenching catalysts are of interest for potential application as biochemical tools for interrogating interbacterial communication pathways, as antibiofouling agents, and as anti-infective agents in plants and animals. Herein, the structure and function of AidC, an N-acyl-l-homoserine lactone (AHL) lactonase from Chryseobacterium, is characterized. Steady-state kinetics show that zinc-supplemented AidC is the most efficient wild-type quorum-quenching enzymes characterized to date, with a k cat/K M value of approximately 2 × 10 6 M -1 s -1 for N-heptanoyl-l-homoserine lactone. The enzyme has stricter substrate selectivity and significantly lower KM values (ca. 50 μM for preferred substrates) compared to those of typical AHL lactonases (ca. ,1 mM). X-ray crystal structures of AidC alone and with the product N-hexanoyl-l-homoserine were determined at resolutions of 1.09 and 1.67 Å, respectively. Each structure displays as a dimer, and dimeric oligiomerization was also observed in solution ...
A series of synthetic molecules combining a geranyl backbone with a heterocyclic or oxime head group are quorum-sensing molecules that block the yeast to mycelium transition in the dimorphic fungus Candida albicans. A number of the analogs have an IC50 ≤ 10 μM, a level of potency essentially identical to the natural quorum sensing signal, the sesquiterpene farnesol. Two of the most potent analogs, neither toxic toward healthy mice, display remarkably different effects when co-administered with C. albicans. While neither offers protection from candidiasis, one analog mimics farnesol in acting as a virulence factor, whereas the other has no effect. The results offer the first example of highly potent synthetic fungal quorum-sensing molecules, and provide the first evidence for the ability to decouple quorum sensing and virulence.
Quorum sensing regulation, mediated by N-acyl homoserine lactone signals, produced by strain Serratia plymuthica HRO-C48 isolated from the rhizosphere of oilseed rape, was found to be responsible for
Vibrio harveyi has been reported to enter into a viable but nonculturable (VBNC) state. Two clinical V. harveyi strains, SF1 and CW2, and the type strain, VIB295(T), were incubated in sterilized seawater at 4 degrees C. Plate counts in these strains
Characterization of novel pathogenic pathways in cancer: do tumor cells use quorum-sensing molecules to support malignancy? at The University of Chicago ...
Introduction: Aspartokinase (A1, A2, A3) Homoserine dehydrogenase (B1, B2) Threonine dehydratase (C1, C2) Allosteric regulation of selective isozymes some unregulated Sequential feedback inhibition Same product inhibits its biosynthetic path at multiple sites Inhibits first enzyme in pathway
Homocysteine, Cystathionine, Escherichia, Escherichia Coli, Active Site, Enzymes, Ammonia, Homoserine, Plants, Hydrolysis, Bacteria, Role, Specificity, Play, Pyridoxal, Pyridoxal 5-phosphate, Roles, CAT, Engineering, PH
Structure of PvdQ bound to HTS hit compound 3. (A)Electron density is shown, calculated with coefficients of the formFo-Fc generated prior to building the ligan
Industry expert Tony OLenick asks Mark Garrison of Avon to explain the difference between esters and lactones, such as lactones being esters in a ring formation.
Previous studies on Campylobacter jejuni have demonstrated the role of LuxS in motility, cytolethal distending toxin production, agglutination, and intestinal colonization; however, its direct involvement in virulence has not been reported. In this study, we demonstrate a direct role of luxS in the virulence of C. jejuni in two different animal hosts. The IA3902 strain, a highly virulent sheep abortion strain recently described by our laboratory, along with its isogenic luxS mutant and luxScomplement strains, was inoculated by the oral route into both a pregnant guinea pig virulence model and a chicken colonization model. In both cases, the IA3902luxS mutant demonstrated a complete loss of ability to colonize the intestinal tract. In the pregnant model, the mutant also failed to induce abortion, while the wild-type strain was highly abortifacient. Genetic complementation of the luxSgene fully restored the virulent phenotype in both models. Interestingly, when the organism was inoculated into guinea pigs
CqsA is an enzyme involved in the biosynthesis of cholerae autoinducer-1 (CAI-1), the major Vibrio cholerae autoinducer engaged in quorum sensing. The amino acid sequence of CqsA suggests that it belongs to the family of α-oxoamine synthases that catalyse the condensation of an amino acid to an acyl-CoA substrate. Here we present the apo- and PLP-bound crystal structures of CqsA and confirm that it shares structural homology with the dimeric α-oxoamine synthases, including a conserved PLP-binding site. The chemical structure of CAI-1 suggests that decanoyl-CoA may be one substrate of CqsA and that another substrate may be l-threonine or l-2-aminobutyric acid. A crystal structure of CqsA at 1.9-Å resolution obtained in the presence of PLP and l-threonine reveals an external aldimine that has lost the l-threonine side chain. Similarly, a 1.9-Å-resolution crystal structure of CqsA in the presence of PLP, l-threonine, and decanoyl-CoA shows a trapped external aldimine intermediate, suggesting ...
Interference with bacterial quorum sensing communication provides an anti-virulence strategy to control pathogenic bacteria. Here, using the Enteropathogenic E. coli (EPEC) O103:H2, we showed for the first time that thiophenone TF101 reduced expression of lsrB; the gene encoding the AI-2 receptor. Combined results of transcriptional and phenotypic analyses suggested that TF101 interfere with AI-2 signalling, possibly by competing with AI-2 for binding to LsrB. This is supported by in silico docking prediction of thiophenone TF101 in the LsrB pocket. Transcriptional analyses furthermore showed that thiophenone TF101 interfered with expression of the virulence genes eae and fimH. In addition, TF101 reduced AI-2 induced E. coli adhesion to colorectal adenocarcinoma cells. TF101, on the other hand, did not affect epinephrine or norepinephrine enhanced E. coli adhesion. Overall, our results showed that thiophenone TF101 interfered with virulence expression in E. coli O103:H2, suggestedly by ...
A mathematical model, involving diffusion of extracellular compounds and cell interactions, has been adapted, in order to assess the quorum sensing process occurring in biofilms. Quorum sensing is a diffusion dependent phenomenon; therefore, accumulation levels of extra-cellular substances can directly affect cellular development. In order to modeling quorum sensing from artificially structured microbial consortia (ASMC), accumulation of N-acyl-Lhomoserine lactone (AHL) was studied within a biofilm formed with three bacterial species, Agrobacterium tumefaciens KYC6, Escherichia coli JM109 and green fluorescent protein (GFP), producer and reporter, Escherichia coli JM105. Different artificial biofilm structures or ASMC and conditions were considered when modeling cell behavior under particular experimental situations, such as: accumulation from external addition or internal production of N-acyl-L-homoserine lactone (AHL) in mixed mono- and multi-layered biofilms. Mathematical modeling results ...
Many common bacterial pathogens use chemical signals to coordinate group behaviors. In the canonical quorum sensing (QS) system of V. fischeri, a synthase, LuxI, produces an N-acyl homoserine lactone (AHL) that is recognized by a receptor, LuxR, at high signal density. LuxR is a transcription factor that regulates bioluminescence and other group behaviors at high population density in an AHL dependent manner. SdiA is a LuxR homolog found in Escherichia coli and Salmonella enterica serovar typhimurium. SdiA does not have a corresponding synthase, however, and these species do not produce AHL signals. SdiA does not respond to population density, but rather has been shown to respond to AHLs produced by other bacterial species in its environment. SdiA regulates many aspects of pathogenesis including directing the location of the infection, survival in the mammalian digestive system, and the production of virulence factors. Accordingly, modulation of SdiA activity might be a useful anti-virulence ...
The 1011 ton global annual turnover of chitin has generated extensive interest in the regulation of chitin processing enzyme production in bacteria. Some bacteria regulate chitinase production by N-Acyl-L-homoserine lactone (AHL) mediated quorum sensing. In this study, a description of bacterial community succession during chitin particle colonisation and depolymerisation in activated sludge is presented. It was discovered that Betaproteobacteria and Bacteroidetes lineages dominate chitin colonisation in sludge and that AHLs bind to chitin at concentrations that upregulate AHL dependent transcription in bacterial cells associated with the chitin surface. There was no requirement for high cell density (a quorum) at the chitin surface. Further, N-Acetyl glucosamine (GlcNAc), the monomer of the chitin polymer, is shown to inhibit AHL dependent gene transcription representing a previously unrecognised mechanism by which the chitinase reaction product negatively regulates chitinase production. ...
The recent rapid growth in the biofilm field has spawned a number of new strategies for controlling biofilms. Below are descriptions of a few of these emergent strategies.. For some years it has been known that bacteria communicate with each other via diffusible signal molecules in a process termed "quorum sensing." The discovery that quorum sensing regulates biofilm formation opens the door to interdicting normal biofilm development through the use of quorum sensing inhibitors. This strategy of jamming communication is now moving towards application. One example of such inhibitors are the brominated furanones that block quorum sensing by acyl homoserine lactones, signal molecules used by Gram-negative bacteria. These furanones were first isolated from a marine algae and are thought to be part of the plants natural defense against microbial biofouling. Furanone-based quorum sensing inhibitors have been shown to increase antibiotic sensitivity of Pseudomonas aeruginosa biofilms and improve ...
Acylhomoserine lactone (AHL) analogues in which the amide function is replaced by a triazole group were synthesized and evaluated for their effect on quorum sensing (QS) and biofilm formation in Burkholderia cenocepacia and Pseudomonas aeruginosa. In addition, the influence of the length of the acyl-mimicking chain was investigated. The compounds showed selectivity between two different AHL QS systems. 3-(1H-1,2,3-Triazol-1-yl)dihydrofuran-2(3H)-ones, in which the 4-substituent best resembled the acyl chain of the native AHL molecule exhibited significant QS agonistic and antagonistic activities. Replacing this aliphatic substituent by a phenyl-containing moiety resulted in active inhibitors of QS. The most active compounds showed biofilm inhibitory as well as biofilm eradicating activities in both test organisms. ...
0038] In the β-diketone compound (3), R1 to R3 are determined depending upon the intended pyrimidinylpyrazole compound. Examples of the 3-diketone compound include acetylacetone, 2,4-hexanedione, 3-methyl-2,4-pentanedione, 2-methyl-3,5-hexanedione, 2,4-heptanedione, 3,5-heptanedione, 3-ethyl-2,4-pentanedione, 2-methyl-3,5-heptanedione, 3,5-octanedione, 2,2-dimethyl-3,5-hexanedione, 3-acetyl-4-methyl-2-pentanone, 3-acetyl-2-hexanone, 2,4-octanedione, 6-methyl-2,4-heptanedione, 3-acetyl-5-methyl-2-hexanone, 3-n-butyl-2,4-pentanedione, 2,4-nonanedione, 2-methyl-3,5-octanedione, 2,2-dimethyl-3,5-heptanedione, 2-methyl-4,6-octanedione, 3,5-nonanedione, 3-tert-butyl-2,4-pentanedione, 4,6-nonanedione, 2,6-dimethyl-3,5-heptanedione, 1-cyclopropyl-1,3-butanedione, 1-cyclopropylpentane-1,3-dione, 1-cyclopropyl-4,4-dimethylpentane-1,3-dione, and 1-cyclobutyl-1,3-butanedione; however, they are not limited by these examples. The β-diketone compounds may be synthesized by a publicly known method or ...
The black band disease (BBD) microbial consortium often causes mortality of reef-building corals. Microbial chemical interactions (i.e., quorum sensing (QS) and antimicrobial production) may be involved in the BBD disease process. Culture filtrates (CFs) from over 150 bacterial isolates from BBD and the surface mucopolysaccharide layer (SML) of healthy and diseased corals were screened for acyl homoserine lactone (AHL) and Autoinducer-2 (AI-2) QS signals using bacterial reporter strains. AHLs were detected in all BBD mat samples and nine CFs. More than half of the CFs (~55%) tested positive for AI-2. Approximately 27% of growth challenges conducted among 19 isolates showed significant growth inhibition. These findings demonstrate that QS is actively occurring within the BBD microbial mat and that culturable bacteria from BBD and the coral SML are able to produce QS signals and antimicrobial compounds. This is the first study to identify AHL production in association with active coral disease.

homoserine (thing) by BioTech - Everything2.comhomoserine (thing) by BioTech - Everything2.com

Homoserine is an amino acid which is used by plants and bacteria to make methionine, threonine, and isoleucine (three of the ... homoserine (thing). See all of homoserine, no other writeups in this node. ... Homoserine is an amino acid which is used by plants and bacteria to make methionine, threonine, and isoleucine (three of the ... twenty amino acids used to make proteins). Homoserine is similar to the amino acid serine (another of the twenty amino acids ...
more infohttps://everything2.com/user/BioTech/writeups/homoserine

O-phosphonato-L-homoserine(2-) (CHEBI:57590)O-phosphonato-L-homoserine(2-) (CHEBI:57590)

O-phosphonato-L-homoserine(2−) (CHEBI:57590) has role human metabolite (CHEBI:77746) O-phosphonato-L-homoserine(2−) (CHEBI: ... O-phosphonato-L-homoserine(2−) (CHEBI:57590) is conjugate base of O-phospho-L-homoserine (CHEBI:15961) ... O-phospho-L-homoserine (CHEBI:15961) is conjugate acid of O-phosphonato-L-homoserine(2−) (CHEBI:57590). ... CHEBI:57590 - O-phosphonato-L-homoserine(2−). Main. ChEBI Ontology. Automatic Xrefs. Reactions. Pathways. Models. ...
more infohttps://www.ebi.ac.uk/chebi/searchId.do?chebiId=CHEBI:57590

Homoserine Lactone - DrugBankHomoserine Lactone - DrugBank

Homoserine Lactone. Accession Number. DB02624 (EXPT01784) Type. Small Molecule. Groups. Experimental. Description. Not ...
more infohttps://www.drugbank.ca/drugs/DB02624

ASMscience | Acylated Homoserine LactASMscience | Acylated Homoserine Lact

This chapter reviews the current understanding of acylated homoserine lactone (AHL) signaling in marine bacterial systems ... Buchholtz, C.,, K. F. Nielsen,, D. L. Milton,, J. L. Larsen,, and L. Gram. 2006. Profiling of acylated homoserine lactones of ... Wheeler, G. L.,, K. Tait,, A. Taylor,, C. Brownlee,, and I. Joint. 2006. Acyl-homoserine lactones modulate the settlement rate ... Fuqua, C.,, and A. Eberhard. 1999. Signal generation in autoinduction systems: synthesis of acylated homoserine lactones by ...
more infohttp://www.asmscience.org/content/book/10.1128/9781555815578.ch16

hom - Homoserine dehydrogenase - Mycobacterium leprae (strain TN) - hom gene & proteinhom - Homoserine dehydrogenase - Mycobacterium leprae (strain TN) - hom gene & protein

Homoserine dehydrogenase (hom). This subpathway is part of the pathway L-methionine biosynthesis via de novo pathway, which is ... This protein is involved in step 3 of the subpathway that synthesizes L-homoserine from L-aspartate.. Proteins known to be ... View all proteins of this organism that are known to be involved in the subpathway that synthesizes L-homoserine from L- ... Belongs to the homoserine dehydrogenase family.Curated. Phylogenomic databases. evolutionary genealogy of genes: Non-supervised ...
more infohttp://www.uniprot.org/uniprot/P46806

Self perception in bacteria: quorum sensing with acylated homoserine lactones.  - PubMed - NCBISelf perception in bacteria: quorum sensing with acylated homoserine lactones. - PubMed - NCBI

Self perception in bacteria: quorum sensing with acylated homoserine lactones.. Fuqua C1, Greenberg EP. ... A variety of Gram-negative bacteria produce membrane permeant, acylated homoserine lactone (HL) pheromones that act as cell ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/10066485?dopt=Abstract

Generation of High-Sensitivity Monoclonal Antibodies Specific for Homoserine Lactones | SpringerLinkGeneration of High-Sensitivity Monoclonal Antibodies Specific for Homoserine Lactones | SpringerLink

A number of bacteria use a class of chemical compounds called acyl-homoserine lactones (AHLs) as quorum sensing (QS) signals to ... A number of bacteria use a class of chemical compounds called acyl-homoserine lactones (AHLs) as quorum sensing (QS) signals to ... Pseudomonas aeruginosa Quorum sensing Acyl-homoserine lactones Monoclonal antibodies Anti-infective antibodies ... Palliyil S. (2018) Generation of High-Sensitivity Monoclonal Antibodies Specific for Homoserine Lactones. In: Leoni L., ...
more infohttps://link.springer.com/protocol/10.1007/978-1-4939-7309-5_25

Homoserine - WikipediaHomoserine - Wikipedia

Homoserine (also called isothreonine) is an α-amino acid with the chemical formula HO2CCH(NH2)CH2CH2OH. L-Homoserine is not one ... Homoserine, or its lactone form, is the product of a cyanogen bromide cleavage of a peptide by degradation of methionine. ... Homoserine is an intermediate in the biosynthesis of three essential amino acids: methionine, threonine (an isomer of ... homoserine), and isoleucine. It forms by two reductions of aspartic acid via the intermediacy of aspartate semialdehyde. Berg, ...
more infohttps://en.wikipedia.org/wiki/Homoserine

PLOS ONE: Characterization of diverse homoserine lactone synthases in Escherichia coliPLOS ONE: Characterization of diverse homoserine lactone synthases in Escherichia coli

... by sending and receiving small molecules called homoserine lactones (HSLs). Bioengineers have incorporated quorum sensing ... Characterization of diverse homoserine lactone synthases in Escherichia coli. Fig 5. LuxR induction in solid agar cultures.. ...
more infohttps://journals.plos.org/plosone/article/figure?id=10.1371/journal.pone.0202294.g005

Homoserine kinase - WikipediaHomoserine kinase - Wikipedia

In enzymology, a homoserine kinase (EC 2.7.1.39) is an enzyme that catalyzes the chemical reaction ATP + L-homoserine ⇌ {\ ... The systematic name of this enzyme class is ATP:L-homoserine O-phosphotransferase. Other names in common use include homoserine ... Watanabe Y, Konishi S, Shimura K (1957). "Biosynthesis of threonine from homoserine. VI. Homoserine kinase". J. Biochem. 44: ... the two substrates of this enzyme are ATP and L-homoserine, whereas its two products are ADP and O-phospho-L-homoserine. This ...
more infohttps://en.wikipedia.org/wiki/Homoserine_kinase

RCSB PDB - Protein Feature View 









 - Acyl-homoserine lactone acylase PvdQ - Q9I194 (PVDQ PSEAE)RCSB PDB - Protein Feature View - Acyl-homoserine lactone acylase PvdQ - Q9I194 (PVDQ PSEAE)

Catalyzes the deacylation of acyl-homoserine lactone (AHL or acyl-HSL), releasing homoserine lactone (HSL) and the ... An N-acyl-L-homoserine lactone + H2O = L-homoserine lactone + a carboxylate. UniProt ...
more infohttp://www.rcsb.org/pdb/protein/Q9I194

Inhibition of homoserine dehydrogenase I by L-serine in Escherichia coli.  - PubMed - NCBIInhibition of homoserine dehydrogenase I by L-serine in Escherichia coli. - PubMed - NCBI

Inhibition of homoserine dehydrogenase I by L-serine in Escherichia coli.. Hama H1, Kayahara T, Tsuda M, Tsuchiya T. ... We have reported that a major cause of growth inhibition of Escherichia coli by L-serine is its inhibition of homoserine ... strongly inhibited the HDH I activities in both the forward and reverse reactions between aspartate semialdehyde and homoserine ...
more infohttps://www.ncbi.nlm.nih.gov/pubmed/1907968?dopt=Abstract

thrA - Bifunctional aspartokinase/homoserine dehydrogenase 1 - Escherichia coli (strain K12) - thrA gene & proteinthrA - Bifunctional aspartokinase/homoserine dehydrogenase 1 - Escherichia coli (strain K12) - thrA gene & protein

... homoserine biosynthetic process, lysine biosynthetic process via diaminopimelate ... Bifunctional aspartokinase/homoserine dehydrogenase 1. Alternative name(s):. Aspartokinase I/homoserine dehydrogenase I. Short ... Bifunctional aspartokinase/homoserine dehydrogenase 1 (thrA), Bifunctional aspartokinase/homoserine dehydrogenase 2 (metL) ... Bifunctional aspartokinase/homoserine dehydrogenase 1 (thrA), Bifunctional aspartokinase/homoserine dehydrogenase 2 (metL) ...
more infohttps://www.uniprot.org/uniprot/P00561

Homoserine dehydratase | definition of homoserine dehydratase by Medical dictionaryHomoserine dehydratase | definition of homoserine dehydratase by Medical dictionary

What is homoserine dehydratase? Meaning of homoserine dehydratase medical term. What does homoserine dehydratase mean? ... Looking for online definition of homoserine dehydratase in the Medical Dictionary? homoserine dehydratase explanation free. ... Synonym(s): cystathionase, cysteine desulfhydrase, cystine desulfhydrase, γ-cystathionase, homoserine deaminase, homoserine ... redirected from homoserine dehydratase) cys·ta·thi·o·nine γ-ly·ase. (sistă-thīō-nēn līās), A liver enzyme, requiring ...
more infohttps://medical-dictionary.thefreedictionary.com/homoserine+dehydratase

Human Metabolome Database: Showing metabocard for L-Homoserine (HMDB0000719)Human Metabolome Database: Showing metabocard for L-Homoserine (HMDB0000719)

L-Homoserine. Description. Homoserine is a more reactive variant of the amino acid serine. In this variant, the hydroxyl side ... Homoserine is the final product on the C-terminal end of the N-terminal fragment following a cyanogen bromide cleavage. ( ... Homoserine is therefore unsuitable for forming proteins and has been eliminated from the repertoire of amino acids used by ... Gazarian KG, Gening LV, Gazarian TG: L-Homoserine: a novel excreted metabolic marker of hepatitis B abnormally produced in ...
more infohttp://www.hmdb.ca/metabolites/HMDB0000719

A new regulatory element modulates homoserine lactone-mediated autoinduction of Ti plasmid conjugal transfer. | Journal of...A new regulatory element modulates homoserine lactone-mediated autoinduction of Ti plasmid conjugal transfer. | Journal of...

A new regulatory element modulates homoserine lactone-mediated autoinduction of Ti plasmid conjugal transfer.. I Hwang, D M ... A new regulatory element modulates homoserine lactone-mediated autoinduction of Ti plasmid conjugal transfer. ... A new regulatory element modulates homoserine lactone-mediated autoinduction of Ti plasmid conjugal transfer. ... A new regulatory element modulates homoserine lactone-mediated autoinduction of Ti plasmid conjugal transfer. ...
more infohttps://jb.asm.org/content/177/2/449?ijkey=6514df21108d207e921e20cc03f40b82c477c0c5&keytype2=tf_ipsecsha

Identification of Quorum-Quenching N-Acyl Homoserine Lactonases from Bacillus Species | Applied and Environmental MicrobiologyIdentification of Quorum-Quenching N-Acyl Homoserine Lactonases from Bacillus Species | Applied and Environmental Microbiology

Identification of Quorum-Quenching N-Acyl Homoserine Lactonases from Bacillus Species. Yi-Hu Dong, Andi R. Gusti, Qiong Zhang, ... Identification of Quorum-Quenching N-Acyl Homoserine Lactonases from Bacillus Species. Yi-Hu Dong, Andi R. Gusti, Qiong Zhang, ... Identification of Quorum-Quenching N-Acyl Homoserine Lactonases from Bacillus Species. Yi-Hu Dong, Andi R. Gusti, Qiong Zhang, ... Metabolism of acyl-homoserine lactone quorum-sensing signals by Variovorax paradoxus. J. Bacteriol. 182:6921-6926. ...
more infohttps://aem.asm.org/content/68/4/1754?ijkey=0f8ed3d08863d1dbb1c54bb72ec530b7121afc1f&keytype2=tf_ipsecsha

Attenuation of quorum sensing in the pathogen Acinetobacter baumannii using non-native N-Acyl homoserine lactones. | Sigma...Attenuation of quorum sensing in the pathogen Acinetobacter baumannii using non-native N-Acyl homoserine lactones. | Sigma...

Attenuation of quorum sensing in the pathogen Acinetobacter baumannii using non-native N-Acyl homoserine lactones.. [Danielle M ... A. baumannii uses N-(3-hydroxydodecanoyl)-l-homoserine lactone (OH-dDHL) and its putative cognate receptor, AbaR, for QS. We ... We screened a focused library of synthetic, non-native N-acyl homoserine lactones (AHLs) to identify such compounds, and ...
more infohttps://www.sigmaaldrich.com/catalog/papers/22853441

ASMscience | Acyl-Homoserine LactoneASMscience | Acyl-Homoserine Lactone

... which regulates light production in the light organ of deep sea fish and squid via an acyl-homoserine lactone (AHL) signaling ... Parsek, M. R.,, D. L. Val,, B. L. Hanzelka,, J. E. J. Cronan,, and E. P. Greenberg. 1999. Acyl homoserine-lactone quorum- ... Dunphy, G.,, C. Miyamoto,, and E. Meighen. 1997. A homoserine lactone autoinducer regulates virulence of an insect-pathogenic ... Chapter 17 : Acyl-Homoserine Lactone Biosynthesis: Structure and Mechanism Authors: Mair E. A. Churchill1, Jake P. Herman2 VIEW ...
more infohttps://www.asmscience.org/content/book/10.1128/9781555815578.ch17

Bifunctional aspartokinase/homoserine dehydrogenase elisa and antibodyBifunctional aspartokinase/homoserine dehydrogenase elisa and antibody

Recombinant Protein and Bifunctional aspartokinase/homoserine dehydrogenase Antibody at MyBioSource. Custom ELISA Kit, ... Bifunctional aspartokinase/homoserine dehydrogenase 1. Bifunctional aspartokinase/homoserine dehydrogenase 1 ELISA Kit. ... Bifunctional aspartokinase/homoserine dehydrogenase 2. Bifunctional aspartokinase/homoserine dehydrogenase 2 ELISA Kit. ... Bifunctional aspartokinase/homoserine dehydrogenase. Bifunctional aspartokinase/homoserine dehydrogenase ELISA Kit. ...
more infohttps://www.mybiosource.com/protein_family.php?root=bifunctional-aspartokinase-homoserine-dehydrogenase

Acyl-homoserine lactone acylase elisa and antibodyAcyl-homoserine lactone acylase elisa and antibody

Recombinant Protein and Acyl-homoserine lactone acylase Antibody at MyBioSource. Custom ELISA Kit, Recombinant Protein and ... Acyl-homoserine lactone acylase PvdQ. Acyl-homoserine lactone acylase PvdQ ELISA Kit. Acyl-homoserine lactone acylase PvdQ ... Acyl-homoserine lactone acylase QuiP. Acyl-homoserine lactone acylase QuiP ELISA Kit. Acyl-homoserine lactone acylase QuiP ... Acyl-homoserine lactone acylase PvdQ Antibody. Also known as Acyl-homoserine lactone acylase PvdQ (AHL acylase PvdQ) (Acyl-HSL ...
more infohttps://www.mybiosource.com/protein_family.php?root=acyl-homoserine-lactone-acylase

672-15-1 - L-Homoserine, 99% - L-2-Amino-4-hydroxybutyric acid - H-Hser-OH - L12427 - Alfa Aesar672-15-1 - L-Homoserine, 99% - L-2-Amino-4-hydroxybutyric acid - H-Hser-OH - L12427 - Alfa Aesar

Methionine and threonine synthesis are limited by homoserine availability and not the activity of homoserine kinase in ... L-Homoserine is used in the biosynthesis of methionine, threonine and isoleucine. ...
more infohttps://www.alfa.com/de/catalog/L12427/

IJMS  | Free Full-Text | Imidazolines as Non-Classical Bioisosteres of N-Acyl homoserine lactones and Quorum Sensing Inhibitors...IJMS | Free Full-Text | Imidazolines as Non-Classical Bioisosteres of N-Acyl homoserine lactones and Quorum Sensing Inhibitors...

A series of selected 2-substituted imidazolines were synthesized in moderate to excellent yields by a modification of protocols reported in the literature. They were evaluated as potential non-classical bioisosteres of AHL with the aim of counteracting bacterial pathogenicity. Imidazolines 18a, 18e and 18f at various concentrations reduced the violacein production by Chromobacterium violaceum, suggesting an anti-quorum sensing profile against Gram-negative bacteria. Imidazoline 18b did not affect the production of violacein, but had a bacteriostatic effect at 100 µM and a bactericidal effect at 1 mM. Imidazoline 18a bearing a hexyl phenoxy moiety was the most active compound of the series, rendering a 72% inhibitory effect of quorum sensing at 100 µM. Imidazoline 18f bearing a phenyl nonamide substituent presented an inhibitory effect on quorum sensing at a very low concentration (1 nM), with a reduction percentage of 28%. This compound showed an irregular performance, decreasing inhibition at
more infohttp://www.mdpi.com/1422-0067/13/2/1284/notes

Frontiers | Discovering, Characterizing, and Applying Acyl Homoserine Lactone-Quenching Enzymes to Mitigate Microbe-Associated...Frontiers | Discovering, Characterizing, and Applying Acyl Homoserine Lactone-Quenching Enzymes to Mitigate Microbe-Associated...

In this study, bacterial strains were isolated from Saudi Arabian coastal environments and screened for acyl homoserine lactone ... In this study, bacterial strains were isolated from Saudi Arabian coastal environments and screened for acyl homoserine lactone ... 2015). MomL, a novel marine-derived N-acyl homoserine lactonase from Muricauda olearia. Appl. Environ. Microbiol. 81, 774-782. ... Eight potential QQ enzyme genes from S1-5 and L11 (Table 2) were classified as N-acyl homoserine lactonase (AiiA), ...
more infohttps://www.frontiersin.org/articles/10.3389/fmicb.2019.00823/full

Rosmarinic acid is a homoserine lactone mimic produced by plants that activates a bacterial quorum-sensing regulator | Science...Rosmarinic acid is a homoserine lactone mimic produced by plants that activates a bacterial quorum-sensing regulator | Science...

Homoserine lactone (HSL) molecules function as quorum-sensing signals for Gram-negative bacteria. Plants also produce ... Rosmarinic acid is a homoserine lactone mimic produced by plants that activates a bacterial quorum-sensing regulator ... Rosmarinic acid is a homoserine lactone mimic produced by plants that activates a bacterial quorum-sensing regulator ... Rosmarinic acid is a homoserine lactone mimic produced by plants that activates a bacterial quorum-sensing regulator ...
more infohttp://stke.sciencemag.org/content/9/409/ra1
  • L-homoserine + NAD(P) + = L-aspartate 4-semialdehyde + NAD(P)H. (uniprot.org)
  • This protein is involved in step 3 of the subpathway that synthesizes L-homoserine from L-aspartate. (uniprot.org)
  • L-Serine strongly inhibited the HDH I activities in both the forward and reverse reactions between aspartate semialdehyde and homoserine at a physiological K+ concentration (100 to 200 mM) and physiological pH (7.5) for E. coli cells. (nih.gov)
  • L-homoserine from L-aspartate: step 1/3. (mybiosource.com)
  • However, actual transcription of the tra genes is regulated by autoinduction through the activator TraR and the substituted homoserine lactone second messenger, Agrobacterium autoinducer (AAI). (asm.org)
  • Homoserine is the final product on the C-terminal end of the N-terminal fragment following a cyanogen bromide cleavage. (hmdb.ca)
  • Other names in common use include homoserine kinase (phosphorylating), and HSK. (wikipedia.org)
  • However, activation of the reporter in cells exposed to the poorly effective alkanoyl acyl-HSL N -hexanoyl- l -homoserine lactone (C6-HSL) required the continued presence of the signal. (asm.org)
  • Dianion of O -phospho- L -homoserine having anionic phosphate and carboxy groups and a protonated amino group. (ebi.ac.uk)