6I1Y

Vibrio vulnificus EpsD

6I1Y の概要

• エントリーDOI: 10.2210/pdb6i1y/pdb
• EMDBエントリー: 0326 0327
• 分子名称: General secretion pathway protein GspD (1 entity in total)
• 機能のキーワード: protein transport
• 由来する生物種: Vibrio vulnificus
• タンパク質・核酸の鎖数: 15
• 化学式量合計: 901873.83

構造登録者

Contreras-Martel, C.,Farias Estrozi, L. (登録日: 2018-10-30, 公開日: 2019-04-10, 最終更新日: 2024-05-15)

主引用文献

Howard, S.P.,Estrozi, L.F.,Bertrand, Q.,Contreras-Martel, C.,Strozen, T.,Job, V.,Martins, A.,Fenel, D.,Schoehn, G.,Dessen, A.
Structure and assembly of pilotin-dependent and -independent secretins of the type II secretion system.
Plos Pathog., 15:e1007731-e1007731, 2019

PubMed Abstract: The type II secretion system (T2SS) is a cell envelope-spanning macromolecular complex that is prevalent in Gram-negative bacterial species. It serves as the predominant virulence mechanism of many bacteria including those of the emerging human pathogens Vibrio vulnificus and Aeromonas hydrophila. The system is composed of a core set of highly conserved proteins that assemble an inner membrane platform, a periplasmic pseudopilus and an outer membrane complex termed the secretin. Localization and assembly of secretins in the outer membrane requires recognition of secretin monomers by two different partner systems: an inner membrane accessory complex or a highly sequence-diverse outer membrane lipoprotein, termed the pilotin. In this study, we addressed the question of differential secretin assembly mechanisms by using cryo-electron microscopy to determine the structures of the secretins from A. hydrophila (pilotin-independent ExeD) and V. vulnificus (pilotin-dependent EpsD). These structures, at approximately 3.5 Å resolution, reveal pentadecameric stoichiometries and C-terminal regions that carry a signature motif in the case of a pilotin-dependent assembly mechanism. We solved the crystal structure of the V. vulnificus EpsS pilotin and confirmed the importance of the signature motif for pilotin-dependent secretin assembly by performing modelling with the C-terminus of EpsD. We also show that secretin assembly is essential for membrane integrity and toxin secretion in V. vulnificus and establish that EpsD requires the coordinated activity of both the accessory complex EpsAB and the pilotin EpsS for full assembly and T2SS function. In contrast, mutation of the region of the S-domain that is normally the site of pilotin interactions has little effect on assembly or function of the ExeD secretin. Since secretins are essential outer membrane channels present in a variety of secretion systems, these results provide a structural and functional basis for understanding the key assembly steps for different members of this vast pore-forming family of proteins.

PubMed: 31083688
DOI: 10.1371/journal.ppat.1007731

実験手法

ELECTRON MICROSCOPY (3.4 Å)