scholarly journals T4SP Database 2.0: An Improved Database for Type IV Secretion Systems in Bacterial Genomes with New Online Analysis Tools

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Na Han ◽  
Weiwen Yu ◽  
Yujun Qiang ◽  
Wen Zhang
Keyword(s):  
Recipient Cell ◽  
Bacterial Species ◽  
Genetic Material ◽  
Type Iv Secretion ◽  
Bacterial Strains ◽  
Secretion Systems ◽  
Bacterial Genomes ◽  
Type Iv ◽  
Type Iv Secretion Systems ◽  
User Friendly

Type IV secretion system (T4SS) can mediate the passage of macromolecules across cellular membranes and is essential for virulent and genetic material exchange among bacterial species. The Type IV Secretion Project 2.0 (T4SP 2.0) database is an improved and extended version of the platform released in 2013 aimed at assisting with the detection of Type IV secretion systems (T4SS) in bacterial genomes. This advanced version provides users with web server tools for detecting the existence and variations of T4SS genes online. The new interface for the genome browser provides a user-friendly access to the most complete and accurate resource of T4SS gene information (e.g., gene number, name, type, position, sequence, related articles, and quick links to other webs). Currently, this online database includes T4SS information of 5239 bacterial strains.Conclusions. T4SS is one of the most versatile secretion systems necessary for the virulence and survival of bacteria and the secretion of protein and/or DNA substrates from a donor to a recipient cell. This database on virB/D genes of the T4SS system will help scientists worldwide to improve their knowledge on secretion systems and also identify potential pathogenic mechanisms of various microbial species.

scholarly journals Two type IV secretion systems with different functions in Burkholderia cenocepacia K56-2

Microbiology ◽  
2009 ◽  
Vol 155 (12) ◽  
pp. 4005-4013 ◽  
Author(s):  
Ruifu Zhang ◽  
John J. LiPuma ◽  
Carlos F. Gonzalez
Keyword(s):  
Type Iv Secretion ◽  
Burkholderia Cenocepacia ◽  
Target Cells ◽  
Secretion Systems ◽  
Type Iv ◽  
Plasmid Mobilization ◽  
Type Iv Secretion Systems ◽  
Derivative Plasmid ◽  
Chromosome Ii ◽  
Bacterial Type

Bacterial type IV secretion systems (T4SS) perform two fundamental functions related to pathogenesis: the delivery of effector molecules to eukaryotic target cells, and genetic exchange. Two T4SSs have been identified in Burkholderia cenocepacia K56-2, a representative of the ET12 lineage of the B. cepacia complex (Bcc). The plant tissue watersoaking (Ptw) T4SS encoded on a resident 92 kb plasmid is a chimera composed of VirB/D4 and F-specific subunits, and is responsible for the translocation of effector(s) that have been linked to the Ptw phenotype. The bc-VirB/D4 system located on chromosome II displays homology to the VirB/D4 T4SS of Agrobacterium tumefaciens. In contrast to the Ptw T4SS, the bc-VirB/D4 T4SS was found to be dispensable for Ptw effector(s) secretion, but was found to be involved in plasmid mobilization. The fertility inhibitor Osa did not affect the secretion of Ptw effector(s) via the Ptw system, but did disrupt the mobilization of a RSF1010 derivative plasmid.

scholarly journals The structural biology of type IV secretion systems

2009 ◽  
Vol 7 (10) ◽  
pp. 703-714 ◽  
Author(s):  
Rémi Fronzes ◽  
Peter J. Christie ◽  
Gabriel Waksman
Keyword(s):  
Structural Biology ◽  
Type Iv Secretion ◽  
Secretion Systems ◽  
Type Iv ◽  
Type Iv Secretion Systems

scholarly journals Bacterial Type IV secretion systems: versatile virulence machines

2012 ◽  
Vol 7 (2) ◽  
pp. 241-257 ◽  
Author(s):  
Daniel E Voth ◽  
Laura J Broederdorf ◽  
Joseph G Graham
Keyword(s):  
Type Iv Secretion ◽  
Secretion Systems ◽  
Type Iv ◽  
Type Iv Secretion Systems ◽  
Bacterial Type

scholarly journals Molecular and Structural Analysis of the Helicobacter pylori cag Type IV Secretion System Core Complex

mBio ◽  
2016 ◽  
Vol 7 (1) ◽  
Author(s):  
Arwen E. Frick-Cheng ◽  
Tasia M. Pyburn ◽  
Bradley J. Voss ◽  
W. Hayes McDonald ◽  
Melanie D. Ohi ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Bacterial Species ◽  
Secretion System ◽  
Effector Proteins ◽  
Type Iv Secretion ◽  
Secretion Systems ◽  
Core Complex ◽  
Type Iv ◽  
Membrane Spanning ◽  
H Pylori

ABSTRACT Bacterial type IV secretion systems (T4SSs) can function to export or import DNA, and can deliver effector proteins into a wide range of target cells. Relatively little is known about the structural organization of T4SSs that secrete effector proteins. In this report, we describe the isolation and analysis of a membrane-spanning core complex from the Helicobacter pylori cag T4SS, which has an important role in the pathogenesis of gastric cancer. We show that this complex contains five H. pylori proteins, CagM, CagT, Cag3, CagX, and CagY, each of which is required for cag T4SS activity. CagX and CagY are orthologous to the VirB9 and VirB10 components of T4SSs in other bacterial species, and the other three Cag proteins are unique to H. pylori . Negative stain single-particle electron microscopy revealed complexes 41 nm in diameter, characterized by a 19-nm-diameter central ring linked to an outer ring by spoke-like linkers. Incomplete complexes formed by Δ cag3 or Δ cagT mutants retain the 19-nm-diameter ring but lack an organized outer ring. Immunogold labeling studies confirm that Cag3 is a peripheral component of the complex. The cag T4SS core complex has an overall diameter and structural organization that differ considerably from the corresponding features of conjugative T4SSs. These results highlight specialized features of the H. pylori cag T4SS that are optimized for function in the human gastric mucosal environment. IMPORTANCE Type IV secretion systems (T4SSs) are versatile macromolecular machines that are present in many bacterial species. In this study, we investigated a T4SS found in the bacterium Helicobacter pylori. H. pylori is an important cause of stomach cancer, and the H. pylori T4SS contributes to cancer pathogenesis by mediating entry of CagA (an effector protein regarded as a “bacterial oncoprotein”) into gastric epithelial cells. We isolated and analyzed the membrane-spanning core complex of the H. pylori T4SS and showed that it contains unique proteins unrelated to components of T4SSs in other bacterial species. These results constitute the first structural analysis of the core complex from this important secretion system.

Exploring cargo transport mechanics in the type IV secretion systems

2005 ◽  
Vol 13 (7) ◽  
pp. 295-298 ◽  
Author(s):  
Jianxiong Li ◽  
Sharon G. Wolf ◽  
Michael Elbaum ◽  
Tzvi Tzfira
Keyword(s):  
Type Iv Secretion ◽  
Secretion Systems ◽  
Type Iv ◽  
Cargo Transport ◽  
Type Iv Secretion Systems

scholarly journals AtlA Functions as a Peptidoglycan Lytic Transglycosylase in the Neisseria gonorrhoeae Type IV Secretion System

2007 ◽  
Vol 189 (15) ◽  
pp. 5421-5428 ◽  
Author(s):  
Petra L. Kohler ◽  
Holly L. Hamilton ◽  
Karen Cloud-Hansen ◽  
Joseph P. Dillard
Keyword(s):  
Neisseria Gonorrhoeae ◽  
Secretion System ◽  
Type Iv Secretion ◽  
Type Iv Secretion System ◽  
Secretion Systems ◽  
Lytic Transglycosylases ◽  
Type Iv ◽  
Lytic Transglycosylase ◽  
Enzymatic Function ◽  
Type Iv Secretion Systems

ABSTRACT Type IV secretion systems require peptidoglycan lytic transglycosylases for efficient secretion, but the function of these enzymes is not clear. The type IV secretion system gene cluster of Neisseria gonorrhoeae encodes two peptidoglycan transglycosylase homologues. One, LtgX, is similar to peptidoglycan transglycosylases from other type IV secretion systems. The other, AtlA, is similar to endolysins from bacteriophages and is not similar to any described type IV secretion component. We characterized the enzymatic function of AtlA in order to examine its role in the type IV secretion system. Purified AtlA was found to degrade macromolecular peptidoglycan and to produce 1,6-anhydro peptidoglycan monomers, characteristic of lytic transglycosylase activity. We found that AtlA can functionally replace the lambda endolysin to lyse Escherichia coli. In contrast, a sensitive measure of lysis demonstrated that AtlA does not lyse gonococci expressing it or gonococci cocultured with an AtlA-expressing strain. The gonococcal type IV secretion system secretes DNA during growth. A deletion of ltgX or a substitution in the putative active site of AtlA severely decreased DNA secretion. These results indicate that AtlA and LtgX are actively involved in type IV secretion and that AtlA is not involved in lysis of gonococci to release DNA. This is the first demonstration that a type IV secretion peptidoglycanase has lytic transglycosylase activity. These data show that AtlA plays a role in type IV secretion of DNA that requires peptidoglycan breakdown without cell lysis.

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