protein secretion by the type II secretion system / type II protein secretion system complex / membrane => GO:0016020 / plasma membrane 類似検索 - 分子機能
Type II secretion system protein GspG / Type II secretion system protein GspG, C-terminal / Type II secretion system (T2SS), protein G / Bacterial general secretion pathway protein G-type pilin / Prokaryotic N-terminal methylation site. / Prokaryotic N-terminal methylation motif / Prokaryotic N-terminal methylation site / Pilin-like 類似検索 - ドメイン・相同性
Type II secretion system core protein G 類似検索 - 構成要素
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM122510
米国
European Union (EU)
FP7-IDEAS-ERC 294809
European Union
Agence Nationale de la Recherche
ANR-14-CE09-0004
フランス
引用
ジャーナル: Nat Microbiol / 年: 2017 タイトル: Structure of the calcium-dependent type 2 secretion pseudopilus. 著者: Aracelys López-Castilla / Jenny-Lee Thomassin / Benjamin Bardiaux / Weili Zheng / Mangayarkarasi Nivaskumar / Xiong Yu / Michael Nilges / Edward H Egelman / Nadia Izadi-Pruneyre / Olivera Francetic / 要旨: Many Gram-negative bacteria use type 2 secretion systems (T2SSs) to secrete proteins involved in virulence and adaptation. Transport of folded proteins via T2SS nanomachines requires the assembly of ...Many Gram-negative bacteria use type 2 secretion systems (T2SSs) to secrete proteins involved in virulence and adaptation. Transport of folded proteins via T2SS nanomachines requires the assembly of inner membrane-anchored fibres called pseudopili. Although efficient pseudopilus assembly is essential for protein secretion, structure-based functional analyses are required to unravel the mechanistic link between these processes. Here, we report an atomic model for a T2SS pseudopilus from Klebsiella oxytoca, obtained by fitting the NMR structure of its calcium-bound subunit PulG into the ~5-Å-resolution cryo-electron microscopy reconstruction of assembled fibres. This structure reveals the comprehensive network of inter-subunit contacts and unexpected features, including a disordered central region of the PulG helical stem, and highly flexible C-terminal residues on the fibre surface. NMR, mutagenesis and functional analyses highlight the key role of calcium in PulG folding and stability. Fibre disassembly in the absence of calcium provides a basis for pseudopilus length control, essential for protein secretion, and supports the Archimedes screw model for the type 2 secretion mechanism.