Two-Partner Secretion: Combining Efficiency and Simplicity in the Secretion of Large Proteins for Bacteria-Host and Bacteria-Bacteria Interactions

Frontiers in Cellular and Infection Microbiology

Bigot, Sarah¹  Jacob-Dubuisson, Franç²  Buchanan, Susan K.⁴  oise⁹  Gué⁹  rin, Jeremy^1,10  Schneider, Robert^1,11 

[1] Lyon 1, Institute of Biology and Chemistry of Proteins, Lyon, France;de Glycobiologie Structurale et Fonctionnelle, Lille, France;de Lille, Centre National de La Recherche Scientifique, Institut National de La Santéde Lille, Centre National de La Recherche Scientifique, UMR 8576–Unitéde Lille, Lille, France;et de La Recherche MéImmunitéInfection et d'Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA;Molecular Microbiology and Structural Biochemistry, Centre National de La Recherche Scientifique UMR 5086–UniversitéNMR and Molecular Interactions, UniversitéUniversitédicale, CHU Lille, Institut Pasteur de Lille, U1019–UMR 8204–Centre d'

关键词: Gram-Negative Bacteria;    protein secretion;    transporters;    Effector proteins;    outer membrane;    Omp85;    bacterial pathogens;    Toxin/antitoxin;   

DOI  :  10.3389/fcimb.2017.00148

学科分类：生物科学（综合）

来源: Frontiers

【 摘 要 】

Initially identified in pathogenic Gram-negative bacteria, the two-partner secretion (TPS) pathway, also known as Type Vb secretion, mediates the translocation across the outer membrane of large effector proteins involved in interactions between these pathogens and their hosts. More recently, distinct TPS systems have been shown to secrete toxic effector domains that participate in inter-bacterial competition or cooperation. The effects of these systems are based on kin versus non-kin molecular recognition mediated by specific immunity proteins. With these new toxin-antitoxin systems, the range of TPS effector functions has thus been extended from cytolysis, adhesion and iron acquisition to genome maintenance, inter-bacterial killing and inter-bacterial signaling. Basically, a TPS system is made up of two proteins, the secreted TpsA effector protein and its TpsB partner transporter, with possible additional factors such as immunity proteins for protection against cognate toxic effectors. Structural studies have indicated that TpsA proteins mainly form elongated β helices that may be followed by specific functional domains. TpsB proteins belong to the Omp85 superfamily. Open questions remain on the mechanism of protein secretion in the absence of ATP or an electrochemical gradient across the outer membrane. The remarkable dynamics of TpsB transporters and the progressive folding of their TpsA partners at the bacterial surface in the course of translocation are thought to be key elements driving the secretion process.

【 授权许可】

CC BY