Conformational flexibility of the protein insertase BamA in the native asymmetric bilayer elucidated by ESR spectroscopy

  • The β-barrel assembly machinery (BAM) consisting of the central β-barrel BamA and four other lipoproteins mediates the folding of the majority of the outer membrane proteins. BamA is placed in an asymmetric bilayer and its lateral gate is suggested to be the functional hotspot. Here we used in situ pulsed electron-electron double resonance spectroscopy to characterize BamA in the native outer membrane. In the detergent micelles, the data is consistent with mainly an inward-open conformation of BamA. The native membrane considerably enhanced the conformational heterogeneity. The lateral gate and the extracellular loop 3 exist in an equilibrium between different conformations. The outer membrane provides a favorable environment for occupying multiple conformational states independent of the lipoproteins. Our results reveal a highly dynamic behavior of the lateral gate and other key structural elements and provide direct evidence for the conformational modulation of a membrane protein in situ.
Author:Aathira Gopinath, Benesh JosephORCiDGND
Parent Title (German):Angewandte Chemie. International edition
Place of publication:Weinheim
Document Type:Article
Date of Publication (online):2021/11/11
Date of first Publication:2021/11/11
Publishing Institution:Universitätsbibliothek Johann Christian Senckenberg
Release Date:2023/08/17
Tag:PELDOR/DEER spectroscopy; conformational dynamics; membrane proteins; protein structures; structural biology
Issue:2, art. e202113448
Article Number:e202113448
Page Number:6
First Page:1
Last Page:6
This work was financially supported through the Emmy Noether program (JO 1428/1-1) and a large equipment funding (438280639) from the Deutsche Forschungsgemeinschaft and the Science Funding from Johanna Quandt Young Academy at Goethe to B.J. Open Access funding enabled and organized by Projekt DEAL.
Wissenschaftliche Zentren und koordinierte Programme / Zentrum für Biomolekulare Magnetische Resonanz (BMRZ)
Dewey Decimal Classification:5 Naturwissenschaften und Mathematik / 53 Physik / 530 Physik
5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften
Licence (German):License LogoCreative Commons - CC BY - Namensnennung 4.0 International