6HS7

Type VI membrane complex

6HS7 の概要

• エントリーDOI: 10.2210/pdb6hs7/pdb
• EMDBエントリー: 0264
• 分子名称: ImcF-like family protein, Type VI secretion system protein VasD (2 entities in total)
• 機能のキーワード: membrane complex, tether, membrane protein
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 25
• 化学式量合計: 1577252.21

構造登録者

Rapisarda, C.,Fronzes, R. (登録日: 2018-09-28, 公開日: 2019-03-27, 最終更新日: 2024-05-15)

主引用文献

Rapisarda, C.,Cherrak, Y.,Kooger, R.,Schmidt, V.,Pellarin, R.,Logger, L.,Cascales, E.,Pilhofer, M.,Durand, E.,Fronzes, R.
In situand high-resolution cryo-EM structure of a bacterial type VI secretion system membrane complex.
Embo J., 38:-, 2019

PubMed Abstract: Bacteria have evolved macromolecular machineries that secrete effectors and toxins to survive and thrive in diverse environments. The type VI secretion system (T6SS) is a contractile machine that is related to phages. It is composed of a phage tail-like structure inserted in the bacterial cell envelope by a membrane complex (MC) comprising the TssJ, TssL and TssM proteins. We previously reported the low-resolution negative-stain electron microscopy structure of the enteroaggregative MC and proposed a rotational 5-fold symmetry with a TssJ:TssL:TssM stoichiometry of 2:2:2. Here, cryo-electron tomography analyses of the T6SS MC confirm the 5-fold symmetry and identify the regions of the structure that insert into the bacterial membranes. A high-resolution model obtained by single-particle cryo-electron microscopy highlights new features: five additional copies of TssJ, yielding a TssJ:TssL:TssM stoichiometry of 3:2:2, an 11-residue loop in TssM, protruding inside the lumen of the MC and constituting a functionally important periplasmic gate, and hinge regions. Based on these data, we propose an updated model on MC structure and dynamics during T6SS assembly and function.

PubMed: 30877094
DOI: 10.15252/embj.2018100886

実験手法

ELECTRON MICROSCOPY (4.6 Å)