Structures of major pilins in Clostridium perfringens demonstrate dynamic conformational change
Structures of major pilins in Clostridium perfringens demonstrate dynamic conformational change
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产气荚膜梭菌主要菌毛蛋白的结构表现出动态构象变化
DOI：
10.1107/s2059798319009689
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Kamitori Shigehiro
中科院分区：
文献类型：
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作者：
Tamai Eiji;Katayama Seiichi;Sekiya Hiroshi;Nariya Hirofumi;Kamitori Shigehiro
革兰氏阳性菌中的菌毛是与细菌细胞表面相关的柔性杆蛋白，它们在与宿主组织的初始粘附和定植中发挥重要作用。菌毛轴由主要菌毛蛋白的共价聚合形成，并由半胱氨酸转肽酶家族分选酶催化。在这里，产气荚膜梭菌菌株 13 和 SM101 的主要菌毛蛋白以及菌株 SM101 的分选酶的 X 射线结构通过生化分析来检测体内菌毛的形成。菌株 13 的主要菌毛蛋白采用细长结构，在晶体中形成非共价连接的聚合链，产生菌毛纤维结构的实用模型。菌株 SM101 的主要菌毛蛋白采用一种新颖的弯曲结构，并在晶体中形成类似反平行双螺旋的左手扭曲，这可能促进细菌细胞间的相互作用。一项建模研究表明，具有弯曲结构的菌毛蛋白与分选酶有良好的相互作用。菌株 SM101 的主要菌毛蛋白被认为通过动态构象变化处于拉长结构和弯曲结构之间的平衡状态，这可能参与菌毛介导的定植和分选酶介导的菌毛聚合。
Pili in Gram-positive bacteria are flexible rod proteins associated with the bacterial cell surface, and they play important roles in the initial adhesion to host tissues and colonization. The pilus shaft is formed by the covalent polymerization of major pilins, catalyzed by sortases, a family of cysteine transpeptidases. Here, X-ray structures of the major pilins from Clostridium perfringens strains 13 and SM101 and of sortase from strain SM101 are presented with biochemical analysis to detect the formation of pili in vivo. The major pilin from strain 13 adopts an elongated structure to form noncovalently linked polymeric chains in the crystal, yielding a practical model of the pilus fiber structure. The major pilin from strain SM101 adopts a novel bent structure and associates to form a left-handed twist like an antiparallel double helix in the crystal, which is likely to promote bacterial cell–cell interactions. A modeling study showed that pilin with a bent structure interacts favorably with sortase. The major pilin from strain SM101 was considered to be in an equilibrium state between an elongated and a bent structure through dynamic conformational change, which may be involved in pili-mediated colonization and sortase-mediated polymerization of pili.