Structural basis of outer membrane protein insertion by the BAM complex

DOI: 10.1038/nature17199

Authors: Yinghong Gu (Biomedical Research Centre, Norwich Medical School, University of East Anglia) , Huanyu Li (Norwich Research) , Haohao Dong (University of East Anglia,) , Yi Zeng (University of East Anglia,) , Zhengyu Zhang (University of East Anglia,) , Neil G. Paterson (Diamond Light Source) , Phillip J. Stansfeld (University of Oxford) , Zhongshan Wang (University of East Anglia) , Yizheng Zhang (Sichuan University) , Wenjian Wang (Sun Yat-sen University) , Changjiang Dong (University of East Anglia)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Nature , VOL 531 , PAGES 64 - 69

State: Published (Approved)
Published: February 2016
Diamond Proposal Number(s): 9475

Abstract: All Gram-negative bacteria, mitochondria and chloroplasts have outer membrane proteins (OMPs) that perform many fundamental biological processes. The OMPs in Gram-negative bacteria are inserted and folded into the outer membrane by the β-barrel assembly machinery (BAM). The mechanism involved is poorly understood, owing to the absence of a structure of the entire BAM complex. Here we report two crystal structures of the Escherichia coli BAM complex in two distinct states: an inward-open state and a lateral-open state. Our structures reveal that the five polypeptide transport-associated domains of BamA form a ring architecture with four associated lipoproteins, BamB–BamE, in the periplasm. Our structural, functional studies and molecular dynamics simulations indicate that these subunits rotate with respect to the integral membrane β-barrel of BamA to induce movement of the β-strands of the barrel and promote insertion of the nascent OMP.

Journal Keywords: X-ray crystallography; Bacterial structural biology; Membrane structure and assembly

Diamond Keywords: Bacteria

Subject Areas: Biology and Bio-materials


Instruments: I02-Macromolecular Crystallography , I03-Macromolecular Crystallography , I24-Microfocus Macromolecular Crystallography

Added On: 10/03/2016 14:32

Discipline Tags:

Structural biology Life Sciences & Biotech

Technical Tags:

Diffraction Macromolecular Crystallography (MX)