A Distinct Type of Pilus from the Human Microbiome.
A Distinct Type of Pilus from the Human Microbiome.
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DOI：
10.1016/j.cell.2016.03.016
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发表时间：
2016-04-21
期刊：
影响因子：
64.5
通讯作者：
Wilson IA
中科院分区：
文献类型：
--
作者：
Xu Q;Shoji M;Shibata S;Naito M;Sato K;Elsliger MA;Grant JC;Axelrod HL;Chiu HJ;Farr CL;Jaroszewski L;Knuth MW;Deacon AM;Godzik A;Lesley SA;Curtis MA;Nakayama K;Wilson IA
皮利是连接的菌毛蛋白的蛋白质聚合物，其从许多细菌的细胞表面突出并且通常介导粘附和毒力。我们研究了一组来自人类微生物组的20种拟杆菌菌毛蛋白，其结构和组装机制尚不清楚。晶体结构和生化数据揭示了一个不同的蛋白质超家族，具有共同的希腊键β-三明治折叠，具有两个甲状腺素运载蛋白样重复序列，通过链交换机制插入菌毛。中心结构菌毛蛋白的组装机制涉及蛋白酶辅助去除其N-末端β-链，产生延伸的疏水沟，其结合传入菌毛蛋白的C-末端供体链。在尖端和基部的辅助菌毛具有特定于其位置的独特结构特征，允许启动或终止组装。因此，菌毛类杆菌具有不同于其他已知皮利的生物发生机制，并且可能代表不同类型的细菌菌毛。
Pili are proteinaceous polymers of linked pilins that protrude from the cell surface of many bacteria and often mediate adherence and virulence. We investigated a set of 20 Bacteroidia pilins from the human microbiome whose structures and mechanism of assembly were unknown. Crystal structures and biochemical data revealed a diverse protein superfamily with a common Greek-key β-sandwich fold with two transthyretin-like repeats that polymerize into a pilus through a strand-exchange mechanism. The assembly mechanism of the central, structural pilins involves proteinase-assisted removal of their N-terminal β-strand, creating an extended hydrophobic groove that binds the C-terminal donor strands of the incoming pilin. Accessory pilins at the tip and base have unique structural features specific to their location, allowing initiation or termination of the assembly. The bacteroidia pilus therefore has a biogenesis mechanism that is distinct from other known pili and likely represents a different type of bacterial pilus.