The structure of a mycobacterial outer-membrane channel
The structure of a mycobacterial outer-membrane channel
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DOI：
10.1126/science.1094114
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发表时间：
2004-02-20
期刊：
影响因子：
56.9
通讯作者：
Schulz, GE
中科院分区：
文献类型：
--
作者：
Faller, M;Niederweis, M;Schulz, GE
分枝杆菌具有低渗透性的外膜，这使它们对大多数抗生素具有耐药性。亲水营养物质可以通过称为孔蛋白的跨膜通道蛋白进入。对耻垢分枝杆菌（MspA）的主要孔蛋白进行x射线分析，发现其呈均匀的高脚杯状构象，具有单一的中央通道。这是分枝杆菌外膜蛋白的第一个结构。蛋白质数据库中未发现结构相关蛋白。MspA包含两个连续的β桶，它们的非极性外表面在孔蛋白周围形成一条带，在当代模型中，这条带太窄，无法适应分枝杆菌外膜的厚度。
Mycobacteria have low-permeability outer membranes that render them resistant to most antibiotics. Hydrophilic nutrients can enter by way of transmembrane-channel proteins called porins. An x-ray analysis of the main porin from Mycobacterium smegmatis, MspA, revealed a homooctameric goblet-like conformation with a single central channel. This is the first structure of a mycobacterial outermembrane protein. No structure-related protein was found in the Protein Data Bank. MspA contains two consecutive beta barrels with nonpolar outer surfaces that form a ribbon around the porin, which is too narrow to fit the thickness of the mycobacterial outer membrane in contemporary models.