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An extensive repertoire of type III secretion effectors in Escherichia coli O157 and the role of lambdoid phages in their dissemination
被引:357
作者:
Tobe, Toru
Beatson, Scott A.
Taniguchi, Hisaaki
Abe, Hiroyuki
Bailey, Christopher M.
Fivian, Amanda
Younis, Rasha
Matthews, Sophie
Marches, Olivier
Frankel, Gad
Hayashi, Tetsuya
Pallen, Mark J.
机构:
[1] Osaka Univ, Grad Sch Med, Suita, Osaka 5650871, Japan
[2] Univ Birmingham, Sch Med, Birmingham B15 2TT, W Midlands, England
[3] Univ Queensland, Sch Mol & Microbial Sci, Brisbane, Qld 4072, Australia
[4] Univ Tokushima, Inst Enzyme Res, Tokushima 7008503, Japan
[5] Univ London Imperial Coll Sci Technol & Med, Div Cell & Mol Biol, London SW7 2AZ, England
[6] Miyazaki Univ, Frontier Sci Res Ctr, Miyazaki 8991692, Japan
来源:
基金:
英国医学研究理事会;
英国惠康基金;
英国生物技术与生命科学研究理事会;
关键词:
bacterial pathogenesis;
bacterial protein secretion;
bioinformatics;
genomics;
virulence;
D O I:
10.1073/pnas.0604891103
中图分类号:
O [数理科学和化学];
P [天文学、地球科学];
Q [生物科学];
N [自然科学总论];
学科分类号:
07 ;
0710 ;
09 ;
摘要:
Several pathogenic strains of Escherichia coli exploit type III secretion to inject "effector proteins" into human cells, which then subvert eukaryotic cell biology to the bacterium's advantage. We have exploited bioinformatics and experimental approaches to establish that the effector repertoire in the Sakai strain of enterohemorrhagic E. coli (EHEC) O157:H7 is much larger than previously thought. Homology searches led to the identification of > 60 putative effector genes. Thirteen of these were judged to be likely pseudogenes, whereas 49 were judged to be potentially functional. In total, 39 proteins were confirmed experimentally as effectors: 31 through proteomics and 28 through translocation assays. At the protein level, the EHEC effector sequences fall into > 20 families. The largest family, the NleG family, contains 14 members in the Sakai strain alone. EHEC also harbors functional homologs of effectors from plant pathogens (HopPtoH, HopW, AvrA) and from Shigella (OspD, OspE, OspG), and two additional members of the Map/IpgB family. Genes encoding proven or predicted effectors occur in > 20 exchangeable effector loci scattered throughout the chromosome. Crucially, the majority of functional effector genes are encoded by nine exchangeable effector loci that lie within lambdoid prophages. Thus, type III secretion in E. coli is linked to a vast phage "metagenome," acting as a crucible for the evolution of pathogenicity.
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页码:14941 / 14946
页数:6
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