The type 2 secretion system (often referred to as the type II secretion system or the T2SS) is protein secretion machinery found in various species of Gram-negative bacteria, including various human pathogens such as Pseudomonas aeruginosa and Vibrio cholerae. The type II secretion system is one of six protein secretory systems that are commonly found in gram negative bacteria along with the type I secretion system, the type III secretion system, The type IV secretion system, the chaperone/usher pathway, the autotransporter pathway/type V secretion system and the type VI secretion system (some bacteria also utilize the type VII secretion system). Like these other systems, the type II secretion system enables the transport of cytoplasmic proteins across the lipid bilayers that make up the cell membranes in gram negative bacteria. The type II secretion system is a membrane bound protein complex found in Gram-negative bacteria that is used to secrete proteins found in the cytoplasm of the bacteria ...

The type VI secretion system (T6SS) is molecular machine used by a wide range of Gram-negative bacterial species to transport proteins from the interior (cytoplasm or cytosol) of a bacterial cell across the cellular envelope into an adjacent target cell. The T6SS was first identified in 2006 in Vibrio cholerae, which causes cholera. Since then, Type VI secretion systems have been found in a quarter of all Proteobacterial genomes, including pathogens of animals, plants, and humans, as well as soil, environmental or marine bacteria. While most of the early studies of Type VI secretion focused on its role in the pathogenesis of higher organisms, it is now known to function primarily in interbacterial antagonism. The T6SS is thought to resemble an inverted phage extending outward from the bacterial cell surface. It consists of 14 proteins that assemble into three sub-complexes: a phage tail-like tubule, a phage baseplate-like structure, and cell-envelope spanning membrane complex. These three ...

Gram-negative bacteria secrete a wide range of proteins whose functions include biogenesis of organelles, such as pilli and flagella, nutrient acquisition, virulence, and efflux of drugs and other toxins. Six distinct secretion systems have been shown to mediate protein export through the inner and outer membranes of Gram-negative bacteria. These pathways are highly conserved throughout the Gram-negative bacterial species. In Gram-positive bacteria, secreted proteins are commonly translocated across the single membrane by the Sec pathway or the two-arginine (Tat) pathway ...

Pseudomonas syringae is a bacterial plant pathogen that infects a large variety of agricultural crops. Bacteria colonize leaf surfaces and enter plant mesophyll tissue through wounds or stomata. Once inside, P. syringae can alter plant cell signaling pathways and suppress plant defense responses enabling it to grow in the intercellular space in the mesophyll. P. syringae possesses at least two types of virulence factors that suppress plant defense responses: i) small phytotoxin molecules, and ii) effector proteins that are translocated through specialized secretion systems. Gram-negative bacteria possess at least six types of secretion systems. The P. syringae type II and type III secretion systems (T2SS and T3SS) are both involved in secreting proteins that are important for P. syringae pathogenesis. Functions of the other secretion systems have not been explored. This study investigates the role of the newly discovered type VI secretion system (T6SS) in P. syringae interaction with plants. The

Type III secretion systems enable plant and animal bacterial pathogens to deliver virulence proteins into the cytosol of eukaryotic host cells, causing a broad spectrum of diseases including bacteremia, septicemia, typhoid fever, and bubonic plague in mammals, and localized lesions, systemic wilting, and blights in plants. In addition, type III secretion systems are also required for biogenesis of the bacterial flagellum. The HrcQ(B) protein, a component of the secretion apparatus of Pseudomonas syringae with homologues in all type III systems, has a variable N-terminal and a conserved C-terminal domain (HrcQ(B)-C). Here, we report the crystal structure of HrcQ(B)-C and show that this domain retains the ability of the full-length protein to interact with other type III components. A 3D analysis of sequence conservation patterns reveals two clusters of residues potentially involved in protein-protein interactions. Based on the analogies between HrcQ(B) and its flagellum homologues, we propose ...

Tuberculosis is a leading cause of death globally. The causative agent, Mycobacterium tuberculosis, resides primarily in so-called macrophages, a type of immune cell that normally serves to kill invading bacteria. The mycobacterial ESX-1 type VII secretion system is critical for ability of the bacterium to survive and grow in these cells. Moreover, ESX-1 is known to induce secretion of proinflammatory cytokines, including IL-1ß, as well as cell death to infected cells. Because these functions may have important roles during infection, this project aimed to gain insight into mechanistic basis for ESX-1-induced IL-1 ß secretion and cell death, respectively ...

Mycobacterium abscessus, a rapidly growing mycobacterium (RGM) and an opportunistic human pathogen, is responsible for a wide spectrum of clinical manifestations ranging from pulmonary to skin and soft tissue infections. This intracellular organism can resist the bactericidal defense mechanisms of amoebae and macrophages, an ability that has not been observed in other RGM. M. abscessus can up-regulate several virulence factors during transient infection of amoebae, thereby becoming more virulent in subsequent respiratory infections in mice. Here, we sought to identify the M. abscessus genes required for replication within amoebae. To this end, we constructed and screened a transposon (Tn) insertion library of an M. abscessus subspecies massiliense clinical isolate for attenuated clones. This approach identified five genes within the ESX-4 locus, which in M. abscessus encodes an ESX-4 type VII secretion system that exceptionally also includes the ESX conserved EccE component. To confirm the ...

Expert authors critically review selected important topics in the field of bacterial pathogenesis. A valuable resource. Topics range from a review of the seven most important bacterial secretion systems to an overview of evasion strategies of mycobacteria. Essential reading.

The assembly of the T3SS culminates in the formation of the needle filament [Fig. 2 (10)]. Beyond the base, export apparatus and cytosolic components, which are required for substrate secretion per se, correct formation of the needle filament requires the co-secretion of other early substrates, including the inner rod protein and the needle length regulator [Fig. 2 (10)] (Kimbrough & Miller, 2000; Kubori et al., 2000). In some systems, secretion of needle subunits is assisted by dedicated chaperones that prevent premature filament formation in the bacterial cytosol (Quinaud et al., 2005, 2007; Sun et al., 2008; Chatterjee et al., 2011; Sal-Man et al., 2013). It was shown that secretion of the needle filament subunit is required for export of the other proteins (Kimbrough & Miller, 2000). Marlovits et al. (2006) subsequently observed that variations in the expression ratio of the Salmonella inner rod protein PrgJ and the needle subunit PrgI resulted in changes in needle length and concluded that ...

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This invention relates to a surgical device and methods for accessing and retrieving a tissue mass from a body cavity through a minimally invasive laparoscopic procedure. The device consists of a handle comprising an inner rod, which is rotatably engaged within a tubular member, and a loop adapted to hold a surgical bag. The loop comprises first and second bowed leaf elements, wherein the first bowed leaf element is attached to the inner rod and the second bowed leaf element is attached to the tubular member. The device further has a rotatable articulation, such as a hinge, joining the first and second bowed leaf elements, wherein rotation of the inner rod causes the first bowed leaf element to rotate about the articulation, such that the surgical bag may be opened and closed by rotation of the inner rod.

Bacterial secretory signal peptide expression plasmid with the T7 promoter upstream to drive gene expression (Frame 1 - NcoI site aligned).

Typically comprised of ~12 different scaffold components, prokaryotic type IV secretion systems (T4SSs) translocate a variety of substrates across the cell envelope. Due to the ability to translocate large DNA segments (i.e., mobile genetic elements), some T4SSs contribute to the spread of antimicrobial resistance and virulence genes. Other T4SSs translocate smaller DNA segments and/or proteins into eukaryotic cells (e.g., arthropod, plant and human) in order to benefit bacterial survival. At least eight major groups of T4SSs are described and each group consists of minor variations on a common structural theme. Within a given bacterial genome, combinations of different T4SS groups can be encoded, and sometimes multiple copies of the same T4SS group can be present. As an example, two functionally divergent T4SSs (vir and trw) are found in many species of Bartonella, bacteria that are transmitted by arthropods such as ticks and fleas and cause a range of diseases including endocarditis. In species of

Type III secretion systems (T3SS) in phytopathogenic bacteria were first described in the 80s. However, whereas numerous characterization studies have revealed the basic processes of assembly, structure and function in animal/human pathogenic systems, our knowledge about these processes in plant type III biosystems is considerably small in comparison. Nonetheless, in recent years we have witnessed important breakthroughs in our understanding on how phytopathogens employ, build and regulate their T3SS: new master transcriptional regulators have been discovered, the activity of already described regulators of the system have been thoroughly investigated, quorum sensing regulators and population dynamics have been found to determine the fine activation of the system, new plant-derived signals have been found to upregulate the phytopathogenic T3SS, and more. Moreover, a considerable weaponry of effectors targeting and tuning the plant responses have been identified and protein components of the core

Friday, 26 January 2018, 13:00Add to calendarESX type VII secretion key to mycobacterial host-pathogen interaction Roland Brosch, Institut Pasteur, Integrated Mycobacterial Pathogenomics Unit, 25 Rue du Dr Roux, 75015 Paris, FranceHost: Matthias WilmannsSeminar Room 48e, EMBL Hamburg ...

Microbial communities are shaped by interactions among their constituent members. Some Gram-negative bacteria employ type VI secretion systems (T6SSs) to inject protein toxins into neighboring cells. These interactions have been theorized to affect the composition of host-associated microbiomes, but the role of T6SSs in the evolution of gut communities is not well understood. We report the discovery of two T6SSs and numerous T6SS-associated Rhs toxins within the gut bacteria of honey bees and bumble bees. We sequenced the genomes of 28 strains of Snodgrassella alvi, a characteristic bee gut microbe, and found tremendous variability in their Rhs toxin complements: altogether, these strains appear to encode hundreds of unique toxins ...

Type-III secretion systems (T3SSs) are responsible for the biosynthesis of flagella, and the interaction of many animal and plant pathogens with eukaryotic cells. T3SSs consist of multiple proteins which assemble to form an apparatus capable of exporting proteins through both membranes of Gram-negative bacteria in one step. Proteins conserved amongst T3SSS can be used for analysis of these systems using computational homology searching. By using tools including BLAST and HMMER in conjunction phylogenetic analysis this thesis examines the range of T3SSs, both in terms of the proteins they contain, and also the bacteria which contain them. In silico analysis of several of the conserved components of T3SSs shows similarities between them and other secretion systems, as well as components of ATPases. Use of conserved components allows for identification of T3SS loci in diverse bacteria, in order to assess in the different proteins used by different T3SSs, and to see where, in evolutionary space, ...

T346Hunter :: DESCRIPTION T346Hunter is a web application for the identification of type III, type IV and type VI secretion systems (T3SS, T4SS and T6SS, respectively) in bacterial genomes. ::DEVELOPER T346Hunt

InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites. We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their individual strengths to produce a powerful integrated database and diagnostic tool.

Killing for DNA: The type VI secretion system of Vibrio cholerae fosters horizontal gene transfer 11.30 - 11.45 Leendert Hamoen, University of Amsterdam, ...

Korotkov, K. V., T. L. Johnson, M. G. Jobling, J. Pruneda, E. Pardon, A. Héroux, S. Turley, J. Steyaert, R. K. Holmes, M. Sandkvist, et al., Structural and functional studies on the interaction of GspC and GspD in the type II secretion system., PLoS Pathog, vol. 7, issue 9, pp. e1002228, 2011 Sep. ...

Genetic information processingProtein fateProtein and peptide secretion and traffickingtype VII secretion protein EssC (TIGR03928; HMM-score: 129.6) ...

Whether its through a lab mishap or eating undercooked beef, becoming infected with pathogenic (disease-causing) E. coli is brutal. When E. coli infects a person, it attaches to the intestinal wall and the infection begins. There is a particular set of proteins that E. coli makes that allow the bacterium to be incredibly successful at infection. These structures, called the Type III secretion system, look and act like tiny syringes. They essentially "inject" their own DNA and proteins into the hosts cells. Not only do E. coli use Type III secretion to wreak havoc on the host, but they also can release a chemical called Shiga toxin. This toxin can enter cells, disrupt host protein synthesis, and even burst the intestinal cells. A build up of this toxin is extremely detrimental to the host. Although E. coli infections are relatively uncommon, they are serious business and cant be taken lightly. Now, I dont want you to think all E. coli are bad guys. Most E. coli are an integral part of our ...

Many gram-negative plant pathogenic bacteria have acquired a highly conserved type III secretion system (T3SS) which enables them to inject so called ... ...

Paleontologists still poorly understand the process that sorts the winners from the losers after a major extinction, Jablonski said. His statistical analysis ruled out one of the most straightforward of possible causes - that lineages that have suffered a major blow to their numbers during a mass extinction might be especially extinction-prone in the aftermath because they contain fewer species to buffer against the hard times. Instead, Jablonski found that many of the biggest post-extinction winners had passed through a diversity bottleneck as narrow as the Dead Clade Walking groups ...

The structure of the Tse3-Tsi3 complex associated with the bacterial type VI secretion system of P. aeruginosa has been solved and refined at 1.9 Å resolution. The structural basis of the recognition of the muramidase effector and its inactivation by its cognate immunity protein is revealed. The type VI secretion system (T6SS) is a bacterial protein-export machine that is capable of delivering virulence effectors between Gram-negative bacteria. The T6SS of Pseudomonas aeruginosa transports two lytic enzymes, Tse1 and Tse3, to degrade cell-wall peptidoglycan in the periplasm of rival bacteria that are competing for niches via amidase and muramidase activities, respectively. Two cognate immunity proteins, Tsi1 and Tsi3, are produced by the bacterium to inactivate the two antibacterial effectors, thereby protecting its siblings from self-intoxication. Recently, Tse1-Tsi1 has been structurally characterized. Here, the structure of the Tse3-Tsi3 complex is reported at 1.9 Å resolution. The results ...

Burkholderia cenocepacia is an opportunistic pathogen causing life-threatening infections in cystic fibrosis and other immunocompromised patients. The bacterium survives within macrophages by interfering with typical endocytic trafficking, resulting in delayed maturation of a B. cenocepacia-containing phagosome. We hypothesize that B. cenocepacia alters gene expression after internalization by macrophages, inducing genes involved in intracellular survival and host adaptation. Furthermore, we hypothesize that specialized bacterial secretion systems are involved in the interactions between intracellular bacteria and macrophages. In this work, we characterize later-stage infection of macrophages by B. cenocepacia, showing replication within an acidified endosomal compartment suggestive of a phagolysosome. We examine differential gene expression by intracellular B. cenocepacia using selective capture of transcribed sequences (SCOTS) with both competitive enrichment and microarray analysis. We identified 766

The major research focus of my group is the transport of proteins by the twin arginine protein transport pathway. This pathway, which is found in the cytoplasmic membranes of most bacteria, and the thylakoid membranes of plant chloroplasts, is highly unusual because it transports pre-folded proteins. Protein substrates are targeted to the Tat machinery by N-terminal signal peptides that contain an S/T- R-R-x-F-L-K twin arginine motif. Our aims are to study the function and mechanism of the Tat protein transporter, and the contribution that it makes to the physiology of bacteria. The Gram-positive bacterium Staphylococcus aureus uses an unusual Type VII secretion system to secrete possible virulence factors. In a collaboration with Professor Bill Hunter we have been structurally and biochemically characterising components and substrates of this system. Contact details ...

T4SSs each possess an envelope-spanning channel composed of conserved components termed the core complex. Early biochemical studies showed that VirB7, VirB9 and VirB10 form a transporter subassembly that is both intrinsically stable and stabilizing for other VirB subunits. This core complex from the conjugative pKM101 system provided the first high-resolution images [26]. The core secretion channel is a multimeric VirB7-VirB9-VirB10 complex containing 14 copies of each protein. A cylindrical structure spanning the entire cell envelope is composed of two layers (designated I and O). Each layer forms a double-walled ring-like structure that defines hollow chambers inside the complex (figure 3b). The structure surrounds a central chamber of about 80 Å at its widest point. The N-terminal domains (NTDs) of VirB9 and VirB10 comprise the I layer and this part of the channel is anchored in the IM by an N-terminal transmembrane helix of VirB10. An opening at the base of the I layer spans 55 Å. The O ...

A retractable needle syringe includes a barrel defining a receiver. There is a plunger having an inner rod extending distally from the proximal end. The plunger includes a hollow sleeve that is disposed over and extend beyond an inner rod. The plunger includes a hollow cutter extending from the inner rod and a stopper disposed over the end of the sleeve. The plunger has a displaceable collar to prevent movement of the inner rod with respect to the sleeve, that is by distal force to the plunger by engagement with the proximal end of the barrel allowing the cutting surface to cut through the stopper. There is a hub with a stem, a proximal flange and an engagement. A clip having a proximal foot with an opening therethrough and a distal grip is disposed on the stem of the hub. The proximal foot of the clip is disposed at the distal surface of the flange and the grip at the engagement on the stem. There is a spring disposed about the stem compressed between the receiver and the clip to provide a bias, so

A suture driver for clamping a suture in the hollow passage and a recessed channel thereof and manipulating the suture to and from a surgical site. The driver includes an outer member tube having a closed and pointed distal end for percutaneous introduction into the body of a patient. The outer tube also includes a recessed channel positioned proximal the closed distal end of the hollow passage extending longitudinally therein and for receiving the suture therein. An inner rod is positioned in the passage of the outer tube and has a clamping surface at the distal end thereof for engaging a suture positioned in the recessed channel. The inner rod is slid through the recessed channel to clamp the suture in the hollow passage of the outer tube against another clamping surface at the distal end of the tube. A handle positioned at the proximal end of the outer tube and inner rod is manipulated to slide the inner rod through the recessed channel and clamp the suture in the hollow passage between the two

Enterohemorrhagic Escherichia coli (EHEC) is a common cause of severe hemorrhagic colitis. EHECs virulence is dependent upon a type III secretion system (TTSS) encoded by 41 genes. These genes are organized in several operons clustered in the locus of enterocyte effacement. Most of the locus of enterocyte effacement genes, including grlA and grlR, are positively regulated by Ler, and Ler expression is positively and negatively modulated by GrlA and GrlR, respectively. However, the molecular basis for the GrlA and GrlR activity is still elusive. We have determined the crystal structure of GrlR at 1.9 Å resolution. It consists of a typical β-barrel fold with eight β-strands containing an internal hydrophobic cavity and a plug-like loop on one side of the barrel. Strong hydrophobic interactions between the two β-barrels maintain the dimeric architecture of GrlR. Furthermore, a unique surface-exposed EDED (Glu-Asp-Glu-Asp) motif is identified to be critical for GrlA-GrlR interaction and for the ...

3. Vincent CD, Jeong KC, Sexton J, Buford E, Vogel JP. 2006. The Legionella pneumophila Dot/Icm Type IV Secretion System. In Legionella: State of the Art 30 Years After Its Recognition. Ed. N. Cianciotto et al, ASM Press, Washington, D.C. Pages 184-191 ...

InterPro provides functional analysis of proteins by classifying them into families and predicting domains and important sites. We combine protein signatures from a number of member databases into a single searchable resource, capitalising on their individual strengths to produce a powerful integrated database and diagnostic tool.

The type IV secretion system virB/virD4 is a major virulence determinant for subversion of human endothelial cell (HEC) function. VirB-dependent changes of HEC include massive cytoskeletal rearrangements, a proinflammatory activation by nuclear factor NF-kappa-B, inhibition of early and late events of apoptosis, leading to an increased cell survival, and, at high infection doses, a cytostatic or cytotoxic effect, which interfers with a potent virB-independent mitogenic activity. These changes of HEC require the T4S coupling protein virD4 and at least one of the effector proteins bepA-G. Together with virB11, may be implicated in providing the energy, via hydrolysis of ATP, for the assembly of secretion system and substrate transport ...

Genes in the 5-kb flanking regions if available, or non-core components encoded by the T6SS gene cluster if any. In the Note column,if available, (e) denotes effector while (i) for immunity ...

Genes in the 5-kb flanking regions if available, or non-core components encoded by the T6SS gene cluster if any. In the Note column,if available, (e) denotes effector while (i) for immunity ...

Mycobacterium tuberculosis-induced cellular aggregation is essential for granuloma formation and may assist establishment and early spread of M. tuberculosis infection. The M. tuberculosis ESX1 mutant, which has a non-functional type VII secretion system, induced significantly less production of the host macrophage-derived chemokine fractalkine (CX3CL1). Upon infection of human macrophages ESX1-dependent fractalkine production mediated selective recruitment of CD11b+ monocytic cells and increased infection of neighbouring cells consistent with early local spread of infection. Fractalkine levels were raised in vivo at tuberculous disease sites in humans and were significantly associated with increased CD11b+ monocytic cellular recruitment and extent of granulomatous disease. These findings suggest a novel fractalkine-dependent ESX1-mediated mechanism in early tuberculous disease pathogenesis in humans. Modulation of M. tuberculosis-mediated fractalkine induction may represent a potential ...

Author Summary Mycobacterium tuberculosis is one of the most life-threatening pathogens of all time, having infected one-third of the present human population. There is an urgent need for both novel vaccines and diagnostic strategies. Here, we were able to identify the targets most dominantly recognized by latently infected individual that successfully contain infection. These targets are contained in three broadly genomic antigenic islands, all related to bacterial secretion systems and composed by several distinct ORFs. Thus, our results suggest that vaccination with one or few defined antigens will fail to replicate the response associated with natural immunity. Our analysis also pinpoints that the Th1 cells dominating the response are associated with novel and well-defined phenotypic markers, suggesting that the response is molded by unique MTB associated factors. This study demonstrates further that the approach combining peptide binding predictions with modern high throughput techniques is

Many Gram-negative bacterial pathogens utilize type III secretion systems (TTSSs) for subverting the normal cellular functions of their target eukaryotic cells. The type III secretion apparatus (TTSA) functions like a syringe to inject proteins through an external needle and into a target cells membrane and cytosol. The TTSA basal body spans the bacterial inner and outer membranes, and the external needle is topped with a tip complex that controls the secretion and delivery of translocator and effector proteins. The needle is formed by the polymerization of ~120 copies of a small acidic protein that is conserved among diverse pathogens. At the tip of the needle, a tip complex is assembled by tip proteins into a ring-like structure which serves as a platform for the assembly of the translocon by translocator proteins. We use NMR spectroscopy to understand how the needle is assembled and how the tip complex is assembled on top of the needle. We determined the solution structures of the BsaL ...

The intracellular bacterial pathogen Legionella pneumophila causes an inflammatory pneumonia called Legionnaires Disease. For virulence, L. pneumophila requires a Dot/Icm type IV secretion system that translocates bacterial effectors to the host cytosol. L. pneumophilalacking the Dot/Icm system is recognized by Toll-like receptors (TLRs), leading to a canonical NF-κB-dependent transcriptional response. In addition, L. pneumophila expressing a functional Dot/Icm system potently induces unique transcriptional targets, including proinflammatory genes such as Il23a and Csf2. Here we demonstrate that this Dot/Icm-dependent response, which we term the effector-triggered response (ETR), requires five translocated bacterial effectors that inhibit host protein synthesis. Upon infection of macrophages with virulent L. pneumophila, these five effectors caused a global decrease in host translation, thereby preventing synthesis of IκB, an inhibitor of the NF-κB transcription factor. Thus, macrophages infected

Type III Secretion Systems (T3SS) are complex bacterial structures that provide gram-negative pathogens with a unique virulence mechanism whereby they grow a needle-like structure in order to inject bacterial effector proteins into the cytoplasm of a host cell. Numerous experiments have been performed to understand the structural details of this nanomachine during the past decade. Despite the concerted efforts of molecular and structural biologists, several crucial aspects of the assembly of this structure, such as the regulation of the length of the needle itself, remain unclear. In this work, we used a combination of mathematical and computational techniques to better understand length control based on the timing of substrate switching, which is a possible mechanism for how bacteria ensure that the T3SS needles are neither too short nor too long. In particular, we predicted the form of the needle length distribution based on this mechanism, and found excellent agreement with available ...

Bacteria propel themselves through liquid environments using rotation of a propeller like organelle, the flagellum. Flagella are energized by the membrane ion gradient and enable bacteria to swim towards nutrients and away from harmful substances. This unique nanomachine shares structural and functional similarities to the needle-like injectisome complex that pathogenic bacteria employ to inject virulence factors into eukaryotic host cells. Bacterial flagella and injectisomes contain a specialized protein export system, termed type III secretion, that functions to deliver structural subunits and effector proteins to the outside of the cytoplasmic membrane. Type III secretion systems are made of multiple proteins, however, the function of individual subunits and the molecular mechanism of protein translocation is poorly understood.,br /,The first part of this thesis reports that the flagellar type III secretion system functions as a proton-driven protein exporter and demonstrates that many ...

Bacteria have mechanisms to export proteins for diverse purposes, including colonization of hosts and pathogenesis. A small number of archetypal bacterial secretion machines have been found in several groups of bacteria and mediate a fundamentally distinct secretion process. Perhaps erroneously, proteins called autotransporters have long been thought to be one of these protein secretion systems. Mounting evidence suggests that autotransporters might be substrates to be secreted, not an autonomous transporter system. We have discovered a new translocation and assembly module (TAM) that promotes efficient secretion of autotransporters in proteobacteria. Functional analysis of the TAM in Citrobacter rodentium, Salmonella enterica and Escherichia coli showed that it consists of an Omp85-family protein, TamA, in the outer membrane and TamB in the inner membrane of diverse bacterial species. The discovery of the TAM provides a new target for the development of therapies to inhibit colonization by ...

Here are some interesting proteins worth making in the event that you are able to make large proteins.. green fluorescent protein (GFP). These are especially useful for testing whether or not synthesis worked. Also, other biological pigments.. chromoproteins, like hemoglobin, myoglobin, cytochromes and flavoproteins.. blood clotting factor for hemophiliacs (see "Molecular approaches for improved clotting factors for hemophilia"). Enzymatic conversion of blood types, removal of blood type antigens. Various photoreceptors, including ultraviolet photoreceptors.. gelatin. Whatever protein makes magnetosomes in magnetotactic bacteria (maybe MamK).. MagA - for producing magnetic nanoparticles. type three secretion system is an "injectisome". "Structures similar to Type3SS injectisomes have been proposed to rivet gram negative bacterial outer and inner membranes to help release outer membrane vesicles targeted to deliver bacterial secretions to eukaryotic host or other target cells in vivo.". kinesin ...

trachomatis Inc proteins. To know whether this result also applied to C. pneumo niae, selleck chem inhibitor we raised antibodies against 7 putative Inc proteins from C. pneumoniae as GST tagged fusion proteins. As a control we used antibodies against the C. pneumoniae Inc protein CPn0186. The anti fusion protein antibodies were used to localize the endogenous proteins in cells infected by C. pneumoniae for 96 hours. In contrast to the inclusion labeling observed with anti CPn0186 antibodies, none of the 7 sera stained the inclusion membrane. The detection of endogenous antigens was removed by pre absorption with corresponding GST fusion proteins but not heterologous Inhibitors,Modulators,Libraries GST fusion proteins, demonstrating the specificity of the antibodies.. While they did not stain the inclusion membrane, the 7 sera labeled the bacteria, demonstrating that the corresponding proteins Inhibitors,Modulators,Libraries are expressed at this stage of infection, and remain bac teria ...

One of the important mechanisms by which H. pylori infection leads to severe gastric disease is through the actions of the bacterial oncoprotein CagA [4], [10], [11], [54]. Translocation of CagA into gastric epithelial cells occurs through a T4SS-mediated process and requires multiple proteins encoded by the cag PAI [12], [14]-[17], [21]. Several H. pylori proteins required for CagA translocation are distantly related to components of T4SSs in other bacterial species and presumably have conserved functions [12], [21], [28], [43]. In the current study, we provide new insights into three components of the cag T4SS that lack homologs in other T4SSs - CagH, CagI, and CagL.. Prior to the current study, it was known that CagL can bind α5β1 integrin and can cause several alterations in host cells [21], [39], [42], [44], [45]. CagL was localized in various studies to several bacterial subcellular sites, including a soluble bacterial fraction [38], [43], the bacterial surface [42], and pili on the ...

Helicobacter pylori is the predominant colonizing prokaryote in the human gastric niche. H. pylori infection results in persistent chronic inflammation, and is...

Vol 9: Assembly of the Type Two Secretion System in Aeromonas hydrophila Involves Direct Interaction between the Periplasmic Domains of the Assembly Factor ExeB and the Secretin ExeD.. This article is from PLoS ONE, volume 9.AbstractThe type two secretion system is a large, trans-envelope apparatus that . Biblioteca virtual para leer y descargar libros, documentos, trabajos y tesis universitarias en PDF. Material universiario, documentación y tareas realizadas por universitarios en nuestra biblioteca. Para descargar gratis y para leer online.

Vol 9: Assembly of the Type Two Secretion System in Aeromonas hydrophila Involves Direct Interaction between the Periplasmic Domains of the Assembly Factor ExeB and the Secretin ExeD.. This article is from PLoS ONE, volume 9.AbstractThe type two secretion system is a large, trans-envelope apparatus that . Download books free in pdf. Online library with books, university works and thousands of documents available to read online and download.

Author Summary Pathogens alter protein expression in an infected host, depending on metabolic or virulence requirements, but the effect of these changes on the immune response is unclear. We identified new class-II epitopes within Salmonella type-III secretion system effector proteins and generated a methodology to visualize endogenous T cells responding to these epitopes. Our study shows that Salmonella flagellin generates a mixed Th1 and Th17 response that contracts early and is enriched in mucosal tissues. In contrast, we found that Salmonella T3SS effectors generate a sustained Th1 response that requires a persisting infection and is enriched in systemic tissues. These data demonstrate that in vivo antigen regulation substantially alters the antigen specificity, helper differentiation, and anatomical location of pathogen-specific CD4 T cells.

A search for factors that are necessary for the pathogenicity of Gram-negative microbes has identified many gene clusters that are closely related among different bacterial species (1). Several of these genetic loci encode type III secretion machines for the translocation of polypeptides across the bacterial double membrane envelope (1). Some mammalian pathogens such as Yersinia, Salmonella, Escherichia coli, Pseudomonas, and Shigella use type III machines for the injection of virulence factors into the cytosol of eukaryotic cells (2-7). A similar strategy is thought to be used by several plant pathogens; however, a direct demonstration of their protein injection has not yet been achieved (7). Salmonella typhimurium and perhaps other Gram-negative bacteria harbor two gene clusters that each specifies a type III machine (2). Mutants that abolish the function of individual type III machines arrest pathogenicity at distinct steps during Salmonella infection, indicating that protein secretion is ...

The archaeal flagellum is a rotating prokaryotic motility apparatus used for swimming motility and adhesion; however, it is more closely related to the bacterial type IV pilus system than its bacterial namesake. Methanococcus ...

Sara V. Pais. PhD Student. Project: Characterization of novel type III secretion effectors of Chlamydia trachomatis. Phone: +351 21 294 8530 ...

L. C. Metzger, S. Stutzmann, T. Scrignari, C. Van der Henst and N. Matthey et al. Independent Regulation of Type VI Secretion in Vibrio cholerae by TfoX and TfoY, in Cell reports, vol. 15, num. 5, p. 951-958, 2016 ...

Professor Dr Yip Cheng Har said that doctors who detect high breast density in their female patients should tell them about the link between the high density and breast cancer. Doctors should also encourage these patients to go for regular mammography screening for breast cancer.

In Gram-negative bacteria, type IV pilus assembly (T4PS) and type II secretion (T2SS) systems polymerize inner membrane proteins called major pilins or pseudopilins respectively, into thin filaments. Four minor pilins are required in both systems for efficient fibre assembly. Escherichia coli K-12 has a set of T4PS assembly genes that are silent under standard growth conditions. We studied the heterologous assembly of the E. coli type IV pilin PpdD by the Klebsiella oxytoca T2SS called the Pul system. PpdD pilus assembly in this context depended on the expression of the K. oxytoca minor pseudopilin genes pulHIJK or of the E. coli minor pilin genes ppdAB-ygdB-ppdC. The E. coli minor pilins restored assembly of the major pseudopilin PulG in a pulHIJK mutant, but not the secretion of the T2SS substrate pullulanase. Thus, minor pilins and minor pseudopilins are functionally interchangeable in initiating major pilin assembly, further extending the fundamental similarities between the two systems. The ...

The type VI secretion system (T6SS), a multisubunit needle-like apparatus, has recently been found to play a role in interspecies interactions. The Gram-negative bacteria harboring T6SS (donor) deliver the effectors into their neighboring cells (recipient) to kill them. Meanwhile, the cognate immunity proteins were employed to protect the donor cells against the toxic effectors. Tae4 (type VI amidase effector 4) and Tai4 (type VI amidase immunity 4) are newly identified T6SS effector-immunity pairs. Here, we report the crystal structures of Tae4 from Enterobacter cloacae and Tae4-Tai4 complexes from both E. cloacae and Salmonella typhimurium. Tae4 acts as a DL-endopeptidase and displays a typical N1pC/P60 domain. Unlike Tsi1 (type VI secretion immunity 1), Tai4 is an all-helical protein and forms a dimer in solution. The small angle x-ray scattering study combined with the analytical ultracentrifugation reveal that the Tae4-Tai4 complex is a compact heterotetramer that consists of a Tai4 dimer ...

Pseudomonas syringae pv. DC3000 is a gram-negative bacterium that infects the model plant Arabidopsis thaliana. Pathogenicity is achieved via secretion of effector proteins into the host cytoplasm through a Type III Secretion System (T3SS). In Ps. DC3000 the T3SS (and associated effector proteins) are dependent on HrpL for their transcription. hrpL transcription is sigma54-dependent and requires two co-dependent enhancer binding proteins, HrpR and HrpS (HrpRS), for activation. HrpRS are regulated by two hrpL-dependent proteins, HrpV and HrpG, where HrpV negatively affects HrpRS activity and HrpG relieves this repression. Here the mechanism of HrpV and HrpGs action on HrpRS activity was tested in vivo and in vitro; and the molecular determinants of HrpV and HrpG functionality were characterised by in silico and mutational analysis. Whole-gene deletion mutants of hrpV and hrpG in Ps. DC3000 revealed complications associated with inserting marker cassettes in transcriptionally-antagonistic ...

Mucispirillum schaedleri is an abundant inhabitant of the intestinal mucus layer of rodents and other animals and has been suggested to be a pathobiont, a commensal that plays a role in disease. In order to gain insights into its lifestyle, we analyzed the genome and transcriptome of M. schaedleri ASF 457 and performed physiological experiments to test traits predicted by its genome. Although described as a mucus inhabitant, M. schaedleri has limited capacity for degrading host-derived mucosal glycans and other complex polysaccharides. Additionally, M. schaedleri reduces nitrate and expresses systems for scavenging oxygen and reactive oxygen species in vivo, which may account for its localization close to the mucosal tissue and expansion during inflammation. Also of note, M. schaedleri harbors a type VI secretion system and putative effector proteins and can modify gene expression in mucosal tissue, suggesting intimate interactions with its host and a possible role in inflammation. The M. ...

Mucispirillum schaedleri is an abundant inhabitant of the intestinal mucus layer of rodents and other animals and has been suggested to be a pathobiont, a commensal that plays a role in disease. In order to gain insights into its lifestyle, we analyzed the genome and transcriptome of M. schaedleri ASF 457 and performed physiological experiments to test traits predicted by its genome. Although described as a mucus inhabitant, M. schaedleri has limited capacity for degrading host-derived mucosal glycans and other complex polysaccharides. Additionally, M. schaedleri reduces nitrate and expresses systems for scavenging oxygen and reactive oxygen species in vivo, which may account for its localization close to the mucosal tissue and expansion during inflammation. Also of note, M. schaedleri harbors a type VI secretion system and putative effector proteins and can modify gene expression in mucosal tissue, suggesting intimate interactions with its host and a possible role in inflammation. The M. ...

HOUSTON--The authors of the life-on-Mars paper that rocked the world last summer (Science, 16 August 1996, p. 924) say they have found further evidence of past life in the famed meteorite: residue from bacterial secretions. The findings, reported here yesterday at the annual Lunar and Planetary Science Conference, were greeted with skepticism from other scientists at the meeting, suggesting that the debate over martian life isnt likely to end soon.. Geochemist Carlton Allen of Lockheed Martin Engineering and Sciences in Houston announced that his group has identified in meteorite ALH84001 the remains of possible "biofilms"--thin layers of carbon that might have been secreted by some tiny long-gone Martian bacteria. Biofilms are aggregates of bacteria attached to a surface and surrounded by a protective coat of mucus or slime, and they are commonplace on Earth; the best known, perhaps, is dental plaque.. Allen reported that the team--headed by David McKay of NASAs Johnson Space Center in ...

Buy TAIGA A320 Online - Bioeffective A 320 also known as Conifer Green Needle Complex. A natural biologically active compound extracted from green conifer needles. CGNC contains vitamins, minerals, fatty and resin acids, chlorophyll, polyprenols, phytoste

p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...

A biopsy device includes an outer cannula, an inner rod, a sheath operably associated with the outer cannula, a handle assembly removably attachable to the sheath, and a release member for releasably attaching the handle assembly to the sheath. In one embodiment, a locking element associated with the sheath comprises a pair of notches located on either side of the sheath, and a locking element associated with the handle assembly comprises a pair of slots in communication with an opening within the handle assembly. The release member comprises a rotatable collar located in a channel on the handle assembly. When the release member is rotated from a first position to a second position, a portion thereof protrudes through the slots into the notches on the sheath, thereby locking the sheath in place.

The strong structural similarity between TrwB and other well known molecular motors, such as the ATP synthase or ring helicases, suggests that TrwB operates as a motor driving a DNA strand through the transport pore, using the energy derived from ATP hydrolysis. TrwB is the best model in a novel group of molecular motors involved in ssDNA transport across membranes; another example of biological molecular motors that convert chemical energy into mechanical work. We work with three ATPases that belong to the type IV secretion system: TrwB, TrwD and TrwK. These three motors are inserted in the inner membrane of the cell and are involved in different functions: DNA transport, protein unfolding and protein transport through the secretion channel, respectively. The results obtained with TrwB have enabled us to propose a common mechanism that could be shared by all members of this family of ATPases, regardless of their role. Continuing with this project, we will carry out structural and biochemical ...

article{SchmidtBalsanelliFaoroEtAl2012, author = {Maria Schmidt and Eduardo Balsanelli and Hellison Faoro and Leonardo M Cruz and Roseli Wassem and Valter A de Baura and Vinicius Weiss and Marshall G Yates and Humberto M F Madeira and Lilian Pereira-Ferrari and Maria H P Fungaro and Francine M de Paula and Luiz F P Pereira and Luiz G E Vieira and Fabio L Olivares and Fabio O Pedrosa and Emanuel M de Souza and Rose A Monteiro}, title = {The type III secretion system is necessary for the development of a pathogenic and endophytic interaction between Herbaspirillum rubrisubalbicans and Poaceae}, journal = {BMC Microbiology}, publisher = {Springer Science $ Business Media}, year = {2012}, volume = {12}, number = {1}, pages = {98}, url = {http://dx.doi.org/10.1186/1471-2180-12-98}, doi = {10.1186/1471-2180-12-98 ...

The PDB archive contains information about experimentally-determined structures of proteins, nucleic acids, and complex assemblies. As a member of the wwPDB, the RCSB PDB curates and annotates PDB data according to agreed upon standards. The RCSB PDB also provides a variety of tools and resources. Users can perform simple and advanced searches based on annotations relating to sequence, structure and function. These molecules are visualized, downloaded, and analyzed by users who range from students to specialized scientists.

Web server == https://rostlab.org/services/pEffect/ == Introduction == The type III secretion system is one of the causes of a wide range of bacterial infections in human, animals and plants. This system comprises a hollow needle-like structure localized on the surface of bacterial cells that injects specific bacterial proteins, the so-called effectors, directly into the cytoplasm of a host cell. During infection, effectors convert host resources to their advantage and promote pathogenicity. We - Tatyana Goldberg, Burkhard Rost and Yana Bromberg - at [http://bromberglab.org BrombergLab] and [http://rostlab.org/cms/ RostLab] developed a novel method, pEffect that predicts bacterial type III effector proteins. In our method, we combine sequence-based homology searches and advanced machine learning to accurately predict effector proteins. We use information encoded in the entire protein sequence for our predictions. == Method design == pEffect is a method that combines sequence ...

The focus of our research is to understand the molecular and cellular events that enable microbial pathogens to evade host defense mechanisms. In particular, we are interested in how bacteria that replicate inside mammalian cells create specialized vacuoles that support pathogen replication. We have been using Legionella pneumophila and Coxiella burnetii as model pathogens to study this process. We have been characterizing a type IV secretion system called Dot/Icm that delivers bacterial effector proteins into the eukaryotic host cell cytosol. The goals of this research are to determine the mechanism by which these bacterial effector proteins regulate phagosome maturation, modulate host immunity, and subvert eukaryotic cell functions.. Specialized Terms: Molecular; Cellular; Microbial pathogens; Bacteria; Vesicular transport; Legionella pneumophila; Coxiella burnetii; Macrophages; Protozoan; ...

p>The checksum is a form of redundancy check that is calculated from the sequence. It is useful for tracking sequence updates.,/p> ,p>It should be noted that while, in theory, two different sequences could have the same checksum value, the likelihood that this would happen is extremely low.,/p> ,p>However UniProtKB may contain entries with identical sequences in case of multiple genes (paralogs).,/p> ,p>The checksum is computed as the sequence 64-bit Cyclic Redundancy Check value (CRC64) using the generator polynomial: x,sup>64,/sup> + x,sup>4,/sup> + x,sup>3,/sup> + x + 1. The algorithm is described in the ISO 3309 standard. ,/p> ,p class="publication">Press W.H., Flannery B.P., Teukolsky S.A. and Vetterling W.T.,br /> ,strong>Cyclic redundancy and other checksums,/strong>,br /> ,a href="http://www.nrbook.com/b/bookcpdf.php">Numerical recipes in C 2nd ed., pp896-902, Cambridge University Press (1993),/a>),/p> Checksum:i ...

Francisella tularensis PdpD protein: a pathogenicity island protein required for full virulence and associates with homologues of the type VI secretion system; RefSeq YP_898955.1

The foliar pathogen Pseudomonas syringae is a useful model for understanding the role of stress adaptation in leaf colonization. We investigated the mechanistic basis of differences in the osmotolerance of two P. syringae strains, B728a and DC3000. Consistent with its higher survival rates following inoculation onto leaves, B728a exhibited superior osmotolerance over DC3000 and higher rates of uptake of plant-derived osmoprotective compounds. A global transcriptome analysis of B728a and DC3000 following an osmotic upshift demonstrated markedly distinct responses between the strains; B728a showed primarily upregulation of genes, including components of the type VI secretion system (T6SS) and alginate biosynthetic pathways, whereas DC3000 showed no change or repression of orthologous genes, including downregulation of the T3SS. DC3000 uniquely exhibited improved growth upon deletion of the biosynthetic genes for the compatible solute N-acetylglutaminylglutamine amide (NAGGN) in a minimal medium, due

Citation: Radwan, O., Carbajulca, D., Libault, M., Brechenmacher, L., Clough, S.J. 2008. Preliminary Analysis of Soybean Gene Expression Response to a Bradyrhizobium japonicum Type III Secretion System Mutant [abstract]. 4th International Conference on Legume Genomics and Genetics, December 7-12, 2008, Puerto Vallarta, Mexico. 2008 CDROM. Interpretive Summary: Technical Abstract: Plant pathogens deliver proteinaceous effector molecules into their host via complex secretion systems, such as the type III secretion system (T3SS). Some of these T3SS effectors have been shown to function as suppressors of host defense responses. The role of the T3SS during plant interactions with symbionts is just beginning to be characterized. The symbiont, Bradyrhizobium japonicum, has a T3SS that is required for proper nodulation of soybean (2002 MPMI 15:1228-1235). Affymetrix gene chip analysis of soybean root-hair response to a T3SS mutant and wild-type B. japonicum versus mock inoculation at 6, 12, and 18 hours ...

Chlamydia trachomatis is an obligate intracellular bacterium associated with trachoma and sexually transmitted diseases. During its intracellular developmental cycle, Chlamydia resides in a membrane bound compartment called the inclusion. A subset of Type III secreted effectors, the inclusion membrane proteins (Inc), are inserted into the inclusion membrane. Inc proteins are strategically positioned to promote inclusion interaction with host factors and organelles, a process required for bacterial replication, but little is known about Inc proteins function or host interacting partners. Moreover, it is unclear whether each Inc protein has a distinct function or if a subset of Inc proteins interacts with one another to perform their function. Here, we used IncD as a model to investigate Inc/Inc interaction in the context of Inc protein expression in C. trachomatis. We developed a co-infection model system to display different tagged Inc proteins on the surface of the same inclusion. We also designed

Klein JA, Dave BM, Raphenya AR, McArthur AG, Knodler LA.. Mol Microbiol. 2017 Mar;103(6):973-991.. Type III Secretion Systems (T3SSs) are structurally conserved nanomachines that span the inner and outer bacterial membranes, and via a protruding needle complex contact host cell membranes and deliver type III effector proteins. T3SS are phylogenetically divided into several families based on structural basal body components. Here we have studied the evolutionary and functional conservation of four T3SS proteins from the Inv/Mxi-Spa family: a cytosolic chaperone, two hydrophobic translocators that form a plasma membrane-integral pore, and the hydrophilic tip complex translocator that connects the T3SS needle to the translocon pore. Salmonella enterica serovar Typhimurium (S. Typhimurium), a common cause of food-borne gastroenteritis, possesses two T3SSs, one belonging to the Inv/Mxi-Spa family. We used invasion-deficient S. Typhimurium mutants as surrogates for expression of translocator ...

The type III secretion system (TTSS) is a key mechanism for host cell interaction used by a variety of bacterial pathogens and symbionts of plants and animals including humans. The TTSS represents a molecular syringe with which the bacteria deliver effector proteins directly into the host cell cytosol. Despite the importance of the TTSS for bacterial pathogenesis, recognition and targeting of type III secreted proteins has up until now been poorly understood. Several hypotheses are discussed, including an mRNA-based signal, a chaperon-mediated process, or an N-terminal signal peptide. In this study, we systematically analyzed the amino acid composition and secondary structure of N-termini of 100 experimentally verified effector proteins. Based on this, we developed a machine-learning approach for the prediction of TTSS effector proteins, taking into account N-terminal sequence features such as frequencies of amino acids, short peptides, or residues with certain physico-chemical properties. The ...

The type III secretion system (TTSS) is a key mechanism for host cell interaction used by a variety of bacterial pathogens and symbionts of plants and animals including humans. The TTSS represents a molecular syringe with which the bacteria deliver effector proteins directly into the host cell cytosol. Despite the importance of the TTSS for bacterial pathogenesis, recognition and targeting of type III secreted proteins has up until now been poorly understood. Several hypotheses are discussed, including an mRNA-based signal, a chaperon-mediated process, or an N-terminal signal peptide. In this study, we systematically analyzed the amino acid composition and secondary structure of N-termini of 100 experimentally verified effector proteins. Based on this, we developed a machine-learning approach for the prediction of TTSS effector proteins, taking into account N-terminal sequence features such as frequencies of amino acids, short peptides, or residues with certain physico-chemical properties. The ...

The present invention provides a process for the production of proteins or protein-containing gene products by transformation of eukaryotic host cells with a recombinant DNA molecule containing the gene for the desired protein, culturing the cells and isolating the gene product after expression, wherein, as host cells, there is used a yeast strain which is deficient in proteases A and B.

Definition of type VI in the Legal Dictionary - by Free online English dictionary and encyclopedia. What is type VI? Meaning of type VI as a legal term. What does type VI mean in law?

Nature. 2012 May 20;486(7402):276-9. doi: 10.1038/nature11079. Research Support, N.I.H., Extramural; Research Support, Non-U.S. Govt

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.

Azoarcus sp. strain BH72 is a mutualistic N2-fixing endophyte of salt-tolerant Kallar grass (Leptochloa fusca (L.) Kunth), a grass gowing in the Punjab of Pakistan. Endophytes are bacteria that live within the tissues of plants without causing them any harm; Azoarcus resides within the roots of its host. Azoarcus sp. strain BH72 is also capable of endophytic N2 fixation in rice and sugarcane. The bacteria has not been detected in root-free soil, although it is able to be cultured. It does not however excrete significant amounts of nitrogenous compounds in culture. The genome sequence has shown that Azoarcus has very few mobile genetic elements, or phage-related genes, suggesting its adaptation to a fairly stable, low-stress environment. The sec-dependent, SRP-mediated and Tat systems for protein secretion are all present, in addition to a type I, the type IIb secretion systems and an autotransporter. However it is lacking both type III and type IV secretion systems, suggesting it can not export ...

Dr. Feng Shaos laboratory is interested in studying molecular mechanisms of bacterial infection and host innate immunity defense. Bacterial pathogens use specialized secretion systems such as type III/IV secretion system to inject effector proteins into host cells, serving as a key and universal virulence mechanism. The effectors usually harbor a unique and potent activity that modulates the function of key signaling molecules in the host, and this plays a critical role in bacterial survival and systemic infections. Using pathogens such as Shigella, Salmonella, Enteropathogenic E. coli (EPEC), Legionella and Burkholderia as the model, we are working to discover and reveal some novel and common biochemical mechanisms utilized by bacterial effectors in modulating host signal transduction pathways. Our recent work has led to several interesting discoveries. 1) The OspF family of type III effectors, conserved in Shigella, Salmonella and the plant pathogen P. syringae, harbors a novel ...

The scientific journal PLOS Pathogens published the paper "Spatiotemporal Regulation of a Legionella pneumophila T4SS Substrate by the Metaeffector SidJ," which was co-written by Emerging Pathogens Institute member Kwang Cheol (K.C.) Jeong Ph.D. The study found and showed mode of action of one of Legionella toxins that is regulating other toxins function to survive in host cells.. "We denominated the toxins role as "metaeffector," Jeong said. "(The article) contains quite interesting findings in pathogenesis mechanisms.". Jeong serves as an assistant professor in the College of Agriculture and Life Sciences (CALS) Department of Animal Science and is part of the Institute of Food and Agricultural Sciences (IFAS). Jeong also runs The Jeong Lab which strives to provide solutions for animal and human health by understanding host-pathogen interactions at the molecular level.. ...

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Hindle, Z, Chatfield, SN, Phillimore, J, Bentley, M, Johnson, J, Cosgrove, CA, Ghaem-Maghami, M, Sexton, A, Khan, M, Brennan, FR, Everest, P, Wu, T, Pickard, D, Holden, DW, Dougan, G, Griffin, GE, House, D, Santangelo, JD, Khan, SA, Shea, JE, Feldman, RG and Lewis, DJ (2002) Characterization of Salmonella enterica derivatives harboring defined aroC and Salmonella pathogenicity island 2 type III secretion system (ssaV) mutations by immunization of healthy volunteers. ...

Having looked at VJs latest screed (on a PC, not an iPad), I have to note approvingly that it has pictures of a butterfly, an artists impression of the multiverse (or the Jovian system four and a half billion years ago - its so hard to tell), a protein, a Scrabble board, a highly idealized picture of a flagellum, a highly idealized picture of a type III secretion system, a highly idealized to the point where its completely blank picture of Ron Numbers, a fossil trilobite, a highly idealized drawing of whale evolution (attributed to Johnathan M. and Uncommon Descent with no clue to where he stole it from), a beaver shot (SFW), a humpbacked whale breaching (possibly from the sheer joy of being a highly evolved product of evolution), a Least Weasel along with a semi-latched reprint from a Douglas Axe article attacking a real scientists paper, a panda that is either eating a piece of bamboo or possibly playing it like a flute (you laugh, but with God, all things are possible) and a fossil ...

Having looked at VJs latest screed (on a PC, not an iPad), I have to note approvingly that it has pictures of a butterfly, an artists impression of the multiverse (or the Jovian system four and a half billion years ago - its so hard to tell), a protein, a Scrabble board, a highly idealized picture of a flagellum, a highly idealized picture of a type III secretion system, a highly idealized to the point where its completely blank picture of Ron Numbers, a fossil trilobite, a highly idealized drawing of whale evolution (attributed to Johnathan M. and Uncommon Descent with no clue to where he stole it from), a beaver shot (SFW), a humpbacked whale breaching (possibly from the sheer joy of being a highly evolved product of evolution), a Least Weasel along with a semi-latched reprint from a Douglas Axe article attacking a real scientists paper, a panda that is either eating a piece of bamboo or possibly playing it like a flute (you laugh, but with God, all things are possible) and a fossil ...

ESAT-6 system 1 (ESX-1)-mediated secretion in Mycobacterium tuberculosis is dependent on proteins encoded by the cotranscribed espA-espC-espD gene cluster. While the roles of EspA and EspC with respect to the ESX-1 secretion system have been actively investigated, the function of EspD remains unknown. We show that EspD is secreted by M. tuberculosis, but unlike EspA and EsxA, its export does not e ...

Gujarat Petroleum has put off by a month plans to hand out information packets on its Krishna Godavari block KG-OSN-2001/3 to seven international majors interested in farming-in to the Deen Dayal...

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Här visas alla kurser som är skapade i LTH:s system för forskarutbildningskurser, och som har tillfällen skapade i Ladok, dvs kurser som är aktuella vald termin. För innevarande och kommande terminer skapas tillfällen löpande och efter att det finns ett tillfälle i Ladok (med status komplett) dyker kursen upp i listan. ...

Abstract. The broad host range pathogenic bacterium Agrobacterium tumefaciens has been widely studied as a model system to understand horizontal gene flow, secretion of effector proteins into host cells, and plant-pathogen interactions. Agrobacterium-mediated plant transformation also is the major method for generating transgenic plants for research and biotechnology purposes. Agrobacterium species have the natural ability to conduct interkingdom genetic transfer from bacteria to eukaryotes, including most plant species, yeast, fungi, and even animal cells. In nature, A. tumefaciens causes crown gall disease resulting from expression in plants of auxin and cytokinin biosynthesis genes encoded by the transferred (T-) DNA. Gene transfer from A. tumefaciens to host cells requires virulence (vir) genes that reside on the resident tumor-inducing (Ti) plasmid. In addition to T-DNA, several Virulence (Vir) effector proteins are also translocated to host cells through a bacterial type IV secretion ...

Used wax dental floss with cheek cells (orange) and bacteria (blue) on dental floss fibres (brown), coloured scanning electron micrograph (SEM). Cheek cells often get scraped from the inside of your mouth when flossing your teeth. Numerous bacteria are present as part of the normal mouth flora. Bacterial plaque consists of a film of bacteria embedded in a glycoprotein matrix. The matrix is formed from bacterial secretions and saliva. The microorganisms that form the plaque biofilm are almost entirely bacteria (mainly Streptococcus mutans and other anaerobes) with the composition varying by location in the mouth. Plaque is the main cause of tooth decay. The bacteria feed on sugars in food, producing acid as a waste product. This acid corrodes the teeths enamel coating, resulting in dental cavities. A build-up of dental plaque can also lead to inflamed and infected gums. Severe gum disease can lead to teeth falling out. Magnification: x500 when - Stock Image F017/3933

Salmonella : environment signaling and genetic regulation of a Type III secretion system in an effort to cause infection Salmonella is a continuing problem throughout the world, contributing to millions of infections every year. These infections are initiated when the bacteria are ingested and then penetrate the M cells of ileal Peyers patches found within the small intestine. Proteins encoded by a cluster of genes on the chromosome known as Salmonella Pathogenicity Island 1 (SPI-1) play an integral role in the invasion process by injecting effector proteins via a type III secretion system directly into the host cells thereby forcing the uptake of the bacteria into the host cell. Salmonella invasion is tightly controlled by the bacterium, and the genes necessary for invasion are activated by specific environmental signals such as low oxygen concentration and high osmolarity, condition that are believed to exist within the small intestine. The hilA gene found within SPI-1 is a transcriptional ...

Entry of the facultative intracellular pathogen Brucella into host cells results in the formation of endosomal Brucella-containing vacuoles (eBCVs) that initially traffic along the endocytic pathway. eBCV acidification triggers the expression of a type IV secretion system that translocates bacterial effector proteins into host cells. This interferes with lysosomal fusion of eBCVs and supports their maturation to replicative Brucella-containing vacuoles (rBCVs). Bacteria replicate in rBCVs to large numbers, eventually occupying most of the cytoplasmic volume. As rBCV membranes tightly wrap each individual bacterium, they are constantly being expanded and remodeled during exponential bacterial growth. rBCVs are known to carry endoplasmic reticulum (ER) markers, however, the relationship of the vacuole to the genuine ER has remained elusive. We have reconstructed the 3-dimensional ultrastructure of rBCVs and associated ER by correlative structured illumination microscopy (SIM) and focused ion ...

Structural Basis for the Serratia marcescens Lipase Secretion System: Crystal Structures of the Membrane FusionProtein and Nucleotide-Binding Domain

Meningococcus (Neisseria meningitidis) causes meningitis and rapidly progressing fatal shock, but only in humans. To invade the brain, meningococcus uses its filamentous pili to hijack the β2-adrenergic receptor (β2AR), inducing an allosteric β-arrestin-biased signaling cascade in endothelial cells lining the capillaries of the brain. This cascade allows bacterial colonies to tether to endothelial cells, despite the shear stress of blood flow, and also promotes opening of endothelial junctions, which allows bacteria to penetrate the brain. Virion et al. sought to understand how a G protein-coupled receptor is activated by bacterial type IV pili proteins to transduce a signaling cascade that normally needs a cognate ligand. They found that β2AR activation requires two asparagine-branched glycan chains with terminally exposed sialic acid residues. Meningococcus triggers receptor signaling by exerting mechanical forces on β2AR glycans with its retractable pili. Because human glycans are ...

Structural studies of biological macromolecular assemblies are providing an understanding of cellular function. In our laboratory, we utilize electron microscopy and image reconstruction to investigate questions about microbial virulence.. Work in the lab currently focuses on bacterial adhesion pili (fimbriae), type III secretion system needles, and virus replication. These projects address basic medical research questions directed at understanding bacterial adhesion to human host tissue and viral replication. Our data support development of novel therapeutics targeting these important health issues including, for example, development of a vaccine against travelers diarrhea.. ...

Chlamydia trachomatis is an obligate intracellular human pathogen causing ocular and urogenital infections that are a significant clinical and public health concern. This bacterium uses a type III secretion (T3S) system to manipulate host cells, through the delivery of effector proteins into their cytosol, membranes, and nucleus. In this work, we aimed to find previously unidentified C. trachomatis T3S substrates. We first analyzed the genome of C. trachomatis L2/434 strain for genes encoding mostly uncharacterized proteins that did not appear to possess a signal of the general secretory pathway and which had not been previously experimentally shown to be T3S substrates. We selected several genes with these characteristics and analyzed T3S of the encoding proteins using Yersinia enterocolitica as a heterologous system. We identified 23 C. trachomatis proteins whose first 20 amino acids were sufficient to drive T3S of the mature form of β-lactamase TEM-1 by Y. enterocolitica. We found that 10 of these

Shigella flexneri is a Gram-negative bacterium that is a significant cause of bacillary dysentery. Shigella uses its type III secretion system (T3SS) to deliver effector proteins into human intestinal cells to alter their functions to promote pathogen entry. The type III secretion apparatus (T3SA) consists of a basal body, an extracellular needle, and a tip complex. As a part of the tip complex, invasion plasmid antigen D (IpaD) controls secretion by acting as an environmental sensor for triggering recruitment of the first "translocator" protein, IpaB, to the bacterial surface. This work extends this knowledge to show that subsequent contact with the host cell triggers T3SS induction and the formation of an IpaB/IpaC translocon pore within the membrane of the host cell. While IpaB is recruited to the TTSA needle tip IpaD senses bile salt in the Shigella environment, IpaC remains within the bacterial cytoplasm. Upon adding liposomes containing cholesterol and sphingolipids, IpaC is recruited to ...

Legionellosis is a potentially fatal infectious disease caused by the bacterium Legionella pneumophila and other legionella species. Two distinct clinical and epidemiological syndromes are associated with Legionella species: Legionnaires disease is the more severe form of the infection, which may involve pneumonia, and Pontiac fever is a milder respiratory illness. The pathogenesis of L. pneumophila is derived from its growth within lung macrophages. One of the L. pneumophilas type IV secretion systems, the Dot/Icm secretion system, is of critical importance for its ability to replicate and to cause disease. The Dot/Icm substrates modulate multiple host cell processes and in particular, redirect trafficking of the L. pneumophila phagosome and mediate its conversion into an ER-derived organelle competent for intracellular bacterial replication. L. pneumophila also manipulates host cell death and survival pathways in a way that allows continued intracellular replication ...