Core architecture of a bacterial type II secretion system
File(s)
Supporting information
Published version
Author(s)
Chernyatina, Anastasia
Low, Harry
Type
Journal Article
Abstract
Bacterial type II secretion systems (T2SSs) translocate virulence factors, toxins and enzymes across the cell outer membrane. Here we use negative stain and cryo-electron microscopy to reveal the core architecture of an assembled T2SS from the pathogen Klebsiella pneumoniae. We show that 7 proteins form a ~2.4 MDa complex that spans the cell envelope. The outer membrane complex includes the secretin PulD, with all domains modelled, and the pilotin PulS. The inner membrane assembly platform components PulC, PulE, PulL, PulM and PulN have a relative stoichiometric ratio of 2:1:1:1:1. The PulE ATPase, PulL and PulM combine to form a flexible hexameric hub. Symmetry mismatch between the outer membrane complex and assembly platform is overcome by PulC linkers spanning the periplasm, with PulC HR domains binding independently at the secretin base. Our results show that the T2SS has a highly dynamic modular architecture, with implication for pseudo-pilus assembly and substrate loading.
Date Issued
2019-11-28
Date Acceptance
2019-10-25
Citation
Nature Communications, 2019, 10 (1)
ISSN
2041-1723
Publisher
Nature Research (part of Springer Nature)
Journal / Book Title
Nature Communications
Volume
10
Issue
1
Copyright Statement
© The Author(s) 2019. Open Access. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Sponsor
Wellcome Trust
Grant Number
097328/Z/11/ZR
Subjects
Science & Technology
Multidisciplinary Sciences
Science & Technology - Other Topics
N-TERMINAL DOMAIN
CRYSTAL-STRUCTURE
STRUCTURAL INSIGHTS
CYTOPLASMIC DOMAIN
INNER MEMBRANE
ATPASE GSPE
CHANNEL
COMPLEX
PROTEIN
PULD
Publication Status
Published
Article Number
5437