6F2D

A FliPQR complex forms the core of the Salmonella type III secretion system export apparatus.

6F2D の概要

• エントリーDOI: 10.2210/pdb6f2d/pdb
• EMDBエントリー: 4173
• 分子名称: Flagellar biosynthetic protein FliP, Flagellar biosynthetic protein FliR, Flagellar biosynthetic protein FliQ (3 entities in total)
• 機能のキーワード: t3ss, flagella, cryo-em, export, membrane protein, protein transport
• 由来する生物種: Salmonella enterica subsp. enterica; 詳細
• タンパク質・核酸の鎖数: 10
• 化学式量合計: 205341.32

構造登録者

Johnson, S.,Kuhlen, L.,Abrusci, P.,Lea, S.M. (登録日: 2017-11-24, 公開日: 2018-07-04, 最終更新日: 2024-05-15)

主引用文献

Kuhlen, L.,Abrusci, P.,Johnson, S.,Gault, J.,Deme, J.,Caesar, J.,Dietsche, T.,Mebrhatu, M.T.,Ganief, T.,Macek, B.,Wagner, S.,Robinson, C.V.,Lea, S.M.
Structure of the core of the type III secretion system export apparatus.
Nat. Struct. Mol. Biol., 25:583-590, 2018

PubMed Abstract: Export of proteins through type III secretion systems is critical for motility and virulence of many major bacterial pathogens. Three putative integral membrane proteins (FliP, FliQ, FliR) are suggested to form the core of an export gate in the inner membrane, but their structure, assembly and location within the final nanomachine remain unclear. Here, we present the cryoelectron microscopy structure of the Salmonella Typhimurium FliP-FliQ-FliR complex at 4.2 Å. None of the subunits adopt canonical integral membrane protein topologies, and common helix-turn-helix structural elements allow them to form a helical assembly with 5:4:1 stoichiometry. Fitting of the structure into reconstructions of intact secretion systems, combined with cross-linking, localize the export gate as a core component of the periplasmic portion of the machinery. This study thereby identifies the export gate as a key element of the secretion channel and implies that it primes the helical architecture of the components assembling downstream.

PubMed: 29967543
DOI: 10.1038/s41594-018-0086-9

実験手法

ELECTRON MICROSCOPY (4.2 Å)