文献类型：期刊文献

英文题名：Chaperone Spy Protects Outer Membrane Proteins from Folding Stress via Dynamic Complex Formation

作者：He, Wei[1];Yu, Gangjin[2];Li, Tianpeng[1];Bai, Ling[1];Yang, Yuanyuan[1];Xue, Zixiao[1,3];Pang, Yonghao[1];Reichmann, Dana[3];Hiller, Sebastian[4];He, Lichun[2,5];Liu, Maili[2,5];Quan, Shu[1]

机构：[1]East China Univ Sci & Technol, Shanghai Collaborat Innovat Ctr Biomfg SCICB, State Key Lab Bioreactor Engn, Shanghai, Peoples R China;[2]Chinese Acad Sci, Innovat Acad Precis Measurement Sci & Technol,Key, Natl Ctr Magnet Resonance Wuhan,Wuhan Natl Lab Op, State Key Lab Magnet Resonance & Atom & Mol Phys, Wuhan, Peoples R China;[3]Hebrew Univ Jerusalem, Alexander Silberman Inst Life Sci, Dept Biol Chem, Safra Campus Givat Ram, Jerusalem, Israel;[4]Univ Basel, Biozentrum, Basel, Switzerland;[5]Univ Chinese Acad Sci, Beijing, Peoples R China

年份：2021

卷号：12

期号：5

外文期刊名：MBIO

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000744187300009)】；

基金：This work was supported by National Natural Science Foundation of China (NSFC) grants 31661143021 and 31400664 (to S.Q.), National Key R&D Program of China grants 2018YFE0202300 (to M.L.) and 2018YFE0202301 (to L.H.), National Natural Sciences Foundation of China grants 21991080 (to M.L.) and 21904138 (to L.H.), the ISF-NSFC joint research program 2629/16 (to D.R.), the Fundamental Research Funds for the Central Universities (grant 22221818014 to S.Q.), the Research Program of State Key Laboratory of Bioreactor Engineering (to S.Q.), and Swiss National Science Foundation grant 185388 (to S.H.).

语种：英文

外文关键词：chaperone; outer membrane protein biogenesis; folding stress; protein-protein interaction; nuclear magnetic resonance spectroscopy

摘要：Gram-negative bacteria have a multicomponent and constitutively active periplasmic chaperone system to ensure the quality control of their outer membrane proteins (OMPs). Recently, OMPs have been identified as a new class of vulnerable targets for antibiotic development, and therefore a comprehensive understanding of OMP quality control network components will be critical for discovering antimicrobials. Here, we demonstrate that the periplasmic chaperone Spy protects certain OMPs against protein-unfolding stress and can functionally compensate for other periplasmic chaperones, namely Skp and FkpA, in the Escherichia coli K-12 MG1655 strain. After extensive in vivo genetic experiments for functional characterization of Spy, we use nuclear magnetic resonance and circular dichroism spectroscopy to elucidate the mechanism by which Spy binds and folds two different OMPs. Along with holding OMP substrates in a dynamic conformational ensemble, Spy binding enables OmpX to form a partially folded beta-strand secondary structure. The bound OMP experiences temperature-dependent conformational exchange within the chaperone, pointing to a multitude of local dynamics. Our findings thus deepen the understanding of functional compensation among periplasmic chaperones during OMP biogenesis and will promote the development of innovative antimicrobials against pathogenic Gram-negative bacteria. IMPORTANCE Outer membrane proteins (OMPs) play critical roles in bacterial pathogenicity and provide a new niche for antibiotic development. A comprehensive understanding of the OMP quality control network will strongly impact antimicrobial discovery. Here, we systematically demonstrate that the periplasmic chaperone Spy has a role in maintaining the homeostasis of certain OMPs. Remarkably, Spy utilizes a unique chaperone mechanism to bind OmpX and allows it to form a partially folded beta-strand secondary structure in a dynamic exchange of conformations. This mechanism differs from that of other E. coli periplasmic chaperones such as Skp and SurA, both of which maintain OMPs in disordered conformations. Our study thus deepens the understanding of the complex OMP quality control system and highlights the differences in the mechanisms of ATP-independent chaperones.