Cryo-EM structures reveal multiple stages of bacterial outer membrane protein folding.
Cryo-EM structures reveal multiple stages of bacterial outer membrane protein folding.
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DOI：
10.1016/j.cell.2022.02.016
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发表时间：
2022-03-31
期刊：
影响因子：
64.5
通讯作者：
Bernstein HD
中科院分区：
文献类型：
--
作者：
Doyle MT;Jimah JR;Dowdy T;Ohlemacher SI;Larion M;Hinshaw JE;Bernstein HD
跨膜β-桶蛋白通过β-桶组装机（BAM）通过一个人们知之甚少的过程折叠到革兰氏阴性细菌的外膜（OM）中，该过程在没有已知外部能源的情况下发生。在这里，我们使用单粒子cryo-EM通过BAM可视化模型β-桶蛋白（EspP）的折叠动力学。我们发现BAM结合EspP的高度保守的“β-信号”基序以在折叠期间正确地定向OM中的β-链。我们还发现EspP的折叠通过“混合桶”中间体进行，其中膜整合的β-折叠连接到必需的BAM亚基BamA。这些结构显示了EspP中间体周围的膜的前所未有的偏转，并表明β-折叠逐渐向BamA折叠以形成β-桶。沿着在OM张力改变时跟踪β-桶折叠的体内实验，我们的结果支持BAM利用OM弹性加速β-桶折叠的模型。通过大肠杆菌中的β-桶组装机制折叠β-桶蛋白EspP涉及在受膜张力影响的过程中将β-折叠逐渐转化为桶样结构。
Transmembrane β-barrel proteins are folded into the outer membrane (OM) of Gram-negative bacteria by the β-barrel assembly machine (BAM) via a poorly understood process that occurs without known external energy sources. Here we used single-particle cryo-EM to visualize the folding dynamics of a model β-barrel protein (EspP) by BAM. We found that BAM binds the highly conserved “β-signal” motif of EspP to correctly orient β-strands in the OM during folding. We also found that the folding of EspP proceeds via “hybrid-barrel” intermediates in which membrane integrated β-sheets are attached to the essential BAM subunit, BamA. The structures show an unprecedented deflection of the membrane surrounding the EspP intermediates and suggest that β-sheets progressively fold towards BamA to form a β-barrel. Along with in vivo experiments that tracked β-barrel folding while the OM tension was modified, our results support a model in which BAM harnesses OM elasticity to accelerate β-barrel folding. The folding of the β-barrel protein EspP by the β-barrel assembly machinery in E.coli involves the progressive conversion of a β-sheet into a barrel-like structure in a process that is influenced by membrane tension.
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DOI：
10.1107/s0907444909052925
发表时间：
2010-02
期刊：
Acta crystallographica. Section D, Biological crystallography
影响因子：
--
作者：
Adams PD;Afonine PV;Bunkóczi G;Chen VB;Davis IW;Echols N;Headd JJ;Hung LW;Kapral GJ;Grosse-Kunstleve RW;McCoy AJ;Moriarty NW;Oeffner R;Read RJ;Richardson DC;Richardson JS;Terwilliger TC;Zwart PH
通讯作者：
Zwart PH
影响因子：
2.9
作者：
Danoff, Emily J.;Fleming, Karen G.
通讯作者：
Fleming, Karen G.
影响因子：
3.6
作者：
Anwari K;Webb CT;Poggio S;Perry AJ;Belousoff M;Celik N;Ramm G;Lovering A;Sockett RE;Smit J;Jacobs-Wagner C;Lithgow T
通讯作者：
Lithgow T
影响因子：
16.6
作者：
Doyle, Matthew T.;Bernstein, Harris D.
通讯作者：
Bernstein, Harris D.
影响因子：
16
作者：
Doyle MT;Bernstein HD
通讯作者：
Bernstein HD