title: A global survey of bacterial type III secretion systems and their effectors.
abstract: The type III secretion system (T3SS) is an important genetic determinant that mediates interactions between Gram-negative bacteria and their eukaryotic hosts. Our understanding of the T3SS continues to expand, yet the availability of new bacterial genomes prompts questions about its diversity, distribution and evolution. Through a comprehensive survey of ∼20 000 bacterial genomes, we identified 174 non-redundant T3SSs from 109 genera and 5 phyla. Many of the bacteria are environmental strains that have not been reported to interact with eukaryotic hosts, while several species groups carry multiple T3SSs. Four ultra-conserved Microsynteny Blocks (MSBs) were defined within the T3SSs, facilitating comprehensive clustering of the T3SSs into 13 major categories, and establishing the largest diversity of T3SSs to date. We subsequently extended our search to identify type III effectors, resulting in 8740 candidate effectors. Lastly, an analysis of the key transcriptional regulators and circuits for the T3SS families revealed that low-level T3SS regulators were more conserved than higher-level regulators. This comprehensive analysis of the T3SSs and their protein effectors provides new insight into the diversity of systems used to facilitate host-bacterial interactions.
authors.affiliation: Department of Cell Biology and Genetics, School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, P.R. China.
authors.forename: Yueming
authors.initials: Y
authors.lastname: Hu
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: He
authors.initials: H
authors.lastname: Huang
authors.affiliation: Department of Cell Biology and Genetics, School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, P.R. China.
authors.forename: Xi
authors.initials: X
authors.lastname: Cheng
authors.affiliation: Department of Cell Biology and Genetics, School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, P.R. China.
authors.forename: Xingsheng
authors.initials: X
authors.lastname: Shu
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: Aaron P
authors.initials: AP
authors.lastname: White
authors.affiliation: Department of Biology, University of Regina, Regina, SK, Canada.
authors.forename: John
authors.initials: J
authors.lastname: Stavrinides
authors.affiliation: Vaccine and Infectious Disease Organization, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Köster
authors.affiliation: College of Veterinary Medicine, Yangzhou University, Yangzhou, China.
authors.forename: Guoqiang
authors.initials: G
authors.lastname: Zhu
authors.affiliation: MOH Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Zhao
authors.affiliation: Department of Cell Biology and Genetics, School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, P.R. China.
authors.forename: Yejun
authors.initials: Y
authors.lastname: Wang
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D016680:Genome, Bacterial / Q000235:genetics; D006090:Gram-Negative Bacteria / Q000235:genetics / Q000378:metabolism*; D054884:Host-Pathogen Interactions / Q000502:physiology; D020560:Proteobacteria / Q000235:genetics / Q000378:metabolism*; D000069296:Type III Secretion Systems / Q000235:genetics / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D000069296:Type III Secretion Systems