Pili or fimbriae, which are filamentous structures present on the surface of bacteria, were purified from a periodontal pathogen, Porphyromonas gingivalis, in 1980s. The protein component of pili (stalk pilin), which is its major component, was named FimA; it has a molecular weight of approximately 41 kDa. Because the molecular weight of the pilin from P. gingivalis is twice that of pilins from other bacterial pili, the P. gingivalis Fim pili were suggested to be formed via a novel mechanism. In earlier studies, we reported that the FimA pilin is secreted on the cell surface as a lipoprotein precursor, and the subsequent N‐terminal processing of the FimA precursor by arginine‐specific proteases is necessary for Fim pili formation. The crystal structures of FimA and its related proteins were determined recently, which show that Fim pili are formed by a protease‐mediated strand‐exchange mechanism. The most recent study conducted by us, wherein we performed cryoelectron microscopy of the pilus structure, provided evidence in support of this mechanism. As the P. gingivalis Fim pili are formed through novel transport and assembly mechanisms, such pili are now designated as Type V pili. Surface lipoproteins, including the anchor pilin FimB of Fim pili that are present on the outer membrane, have been detected in certain Gram‐negative bacteria. Here, we describe the assembly mechanisms of pili, including those of Type V and other pili, as well as the lipoprotein transport mechanisms.

中文翻译：

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V型菌毛的生物发生。

菌毛或菌毛是细菌表面上的丝状结构，在1980年代从牙周病原体牙龈卟啉单胞菌中纯化出来。菌毛的蛋白质成分（茎毛蛋白）是其主要成分，被称为FimA。它的分子量约为41 kDa。因为从菌毛蛋白的分子量牙龈卟啉菌的两倍，从其他细菌菌毛pilins中，牙龈卟啉菌Fim pili被建议通过一种新颖的机制形成。在较早的研究中，我们报道了FimA菌毛蛋白以脂蛋白前体的形式分泌在细胞表面，随后精氨酸特异性蛋白酶对FimA前体进行N末端加工对于形成Fim菌毛是必需的。最近确定了FimA及其相关蛋白的晶体结构，表明Fim菌毛是由蛋白酶介导的链交换机制形成的。我们进行的最新研究（其中我们对菌毛结构进行了冷冻电子显微镜检查）提供了支持该机制的证据。由于牙龈Fim菌毛是通过新颖的运输和组装机制形成的，这种菌毛现在被称为V型菌毛。在某些革兰氏阴性细菌中已检测到表面脂蛋白，包括外膜上存在的Fim pili的锚菌毛蛋白FimB。在这里，我们描述了菌毛的组装机制，包括V型菌毛和其他菌毛的组装机制，以及脂蛋白转运机制。