The big BAM theory: An open and closed case?
The big BAM theory: An open and closed case?
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BAM 大理论：开放式和封闭式案例？
DOI：
10.1016/j.bbamem.2019.183062
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Noinaj,Nicholas
中科院分区：
文献类型：
--
作者：
Wu,Runrun;Stephenson,Robert;Gichaba,Abigail;Noinaj,Nicholas
β-Barrel组装机制负责将外膜蛋白(OMP)生物合成到革兰氏阴性菌的外膜。这些OMP有一个膜嵌入结构域，由一个β桶折叠组成，该折叠可以从8到36个β链变化，每个链在细胞中起着不同的作用，如营养吸收和毒力。BAM在近20年前首次被发现，但直到最近才报道了整个复合体的分子结构。结合多年的功能鉴定，我们对BAM的结构、复合体内的相互作用、BAM在OMP生物发生过程中可能经历的构象变化以及伴侣可能扮演的角色有了更清晰的描述。但是，尽管在过去的二十年里取得了进展，BAM介导的OMP生物发生的机制仍然难以捉摸。多年来，已经提出了几种理论，它们得到了不同程度的文献支持，但还没有一个足够确凿的结论，足以被广泛接受为唯一的机制。我们将简要介绍BAM的历史，最近关于BAM结构的工作，并对当前关于BAM如何发挥作用的理论进行批判性分析。
The β-barrel assembly machinery (BAM) is responsible for the biogenesis of outer membrane proteins (OMPs) into the outer membranes of Gram-negative bacteria. These OMPs have a membrane-embedded domain consisting of a β-barrel fold which can vary from 8 to 36 β-strands, with each serving a diverse role in the cell such as nutrient uptake and virulence. BAM was first identified nearly two decades ago, but only recently has the molecular structure of the full complex been reported. Together with many years of functional characterization, we have a significantly clearer depiction of BAM's structure, the intra-complex interactions, conformational changes that BAM may undergo during OMP biogenesis, and the role chaperones may play. But still, despite advances over the past two decades, the mechanism for BAM-mediated OMP biogenesis remains elusive. Over the years, several theories have been proposed that have varying degrees of support from the literature, but none has of yet been conclusive enough to be widely accepted as the sole mechanism. We will present a brief history of BAM, the recent work on the structures of BAM, and a critical analysis of the current theories for how it may function.