Cell surface display of minor pilin adhesins in the form of a simple heterodimeric assembly in Corynebacterium diphtheriae.
Cell surface display of minor pilin adhesins in the form of a simple heterodimeric assembly in Corynebacterium diphtheriae.
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DOI：
10.1111/j.1365-2958.2010.07515.x
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发表时间：
2011-03
影响因子：
3.6
通讯作者：
Ton-That H
中科院分区：
文献类型：
--
作者：
Chang C;Mandlik A;Das A;Ton-That H
革兰氏阳性菌中的菌毛组装通过两步机制发生，其中菌毛蛋白聚合，然后共价锚定到细胞壁。在白喉棒状杆菌中，菌毛蛋白特异性分选酶SrtA催化SpaA型菌毛的聚合，所述SpaA型菌毛由杆菌毛蛋白SpaA、尖端菌毛蛋白SpaC和次要菌毛蛋白SpaB组成。当SrtA通过赖氨酸介导的转肽作用将SpaB结合到菌毛基底中时，触发SpaA聚合物的细胞壁锚定;随后通过管家分选酶SrtF催化锚定到细胞壁肽聚糖。在这里，我们表明，SpaB和SpaC形成一个异二聚体独立于SpaA聚合。SrtA是绝对需要的SpaBC异二聚体的形成，而SrtF促进了最佳的细胞壁锚定的异二聚体。丙氨酸取代的SpaB赖氨酸残基K139或截断的SpaB细胞壁分选信号（CWSS）废除装配的SpaBC异源二聚体，因此强调SpaB功能的转肽和细胞壁连接。重要的是，发现分选酶对细胞壁锚定步骤的特异性依赖于SpaB CWSS内的LAFTG基序。因此，C.白喉采用一种常见的分选酶催化机制，包括赖氨酸介导的转肽作用，以在细菌细胞壁上产生粘附菌毛和简单的异二聚体结构。
Pilus assembly in gram-positive bacteria occurs by a two-step mechanism, whereby pilins are polymerized and then covalently anchored to the cell wall. In Corynebacterium diphtheriae, the pilin-specific sortase SrtA catalyzes polymerization of the SpaA-type pilus, consisting of the shaft pilin SpaA, tip pilin SpaC and minor pilin SpaB. Cell wall anchoring of the SpaA polymers is triggered when SrtA incorporates SpaB into the pilus base via lysine-mediated transpeptidation; anchoring to the cell wall peptidoglycan is subsequently catalyzed by the housekeeping sortase SrtF. Here we show that SpaB and SpaC formed a heterodimer independent from SpaA polymerization. SrtA was absolutely required for the formation of the SpaBC heterodimer, while SrtF facilitated the optimal cell wall anchoring of this heterodimer. Alanine substitution of the SpaB lysine residue K139 or truncation of the SpaB cell wall sorting signal (CWSS) abolished assembly of the SpaBC heterodimer, hence underscoring SpaB function in transpeptidation and cell wall linkage. Importantly, sortase specificity for the cell wall anchoring step was found to be dependent on the LAFTG motif within the SpaB CWSS. Thus, C. diphtheriae employs a common sortase-catalyzed mechanism involving lysine-mediated transpeptidation to generate both adhesive pilus and simple heterodimeric structures on the bacterial the cell wall.
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影响因子：
3.6
作者：
Hung, TT;Marraffini, LA;Schneewind, O
通讯作者：
Schneewind, O
影响因子：
3.6
作者：
Ton-That, H;Schneewind, O
通讯作者：
Schneewind, O
影响因子：
2.6
作者：
Ankri, S;Reyes, O;Leblon, G
通讯作者：
Leblon, G
影响因子：
4.8
作者：
Budzik, Jonathan M.;Oh, So-Young;Schneewind, Olaf
通讯作者：
Schneewind, Olaf
影响因子：
3.2
作者：
Kline, Kimberly A.;Kau, Andrew L.;Hultgren, Scott J.
通讯作者：
Hultgren, Scott J.