Assembly proteins of CS1 pili of enterotoxigenic Escherichia coli
Assembly proteins of CS1 pili of enterotoxigenic Escherichia coli
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DOI：
10.1111/j.1365-2958.1996.tb02562.x
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发表时间：
1996-08-01
影响因子：
3.6
通讯作者：
Scott, JR
中科院分区：
文献类型：
--
作者：
Sakellaris, H;Balding, DP;Scott, JR
与人类腹泻病相关的一些产肠毒素大肠杆菌菌株产生一类以 CS1 为代表的丸剂，为了将主要菌毛蛋白亚基 CooA 组装成丸剂，需要四个连锁基因 cooB、A、C 和 D 中的每一个。在本研究中，我们确定了 CooB、C 和 D 的亚细胞定位，并使用特定抗血清研究了这些蛋白质的分子相互作用，CooD 似乎是一个不可或缺的组成部分菌毛蛋白，因为它与 CS1 菌毛共纯化，并且与 CS1 菌毛蛋白密切相关。为了与其作为组装蛋白的作用保持一致，CooD 小菌毛蛋白（当在 CS1 菌毛菌株中过表达时）在与主要菌毛蛋白亚基 CooA 的周质分子间复合物中被检测到，CooB 是一种仅在 CS1 菌毛菌株周质中发现的组装蛋白。 CooB 还与 CooA 形成周质分子间复合物，但不构成最终菌毛结构的一部分。细胞组分的免疫印迹分析表明，CooC是CS1-pilated大肠杆菌的外膜蛋白，基于此信息，我们提出了CS1-pilus组装模型，该模型与尿路致病性大肠杆菌的PapA菌毛蛋白聚合模型非常相似，由于Pap和CS1pilus的组装蛋白在结构上不相关，这可能代表趋同进化的情况。
Some strains of enterotoxigenic Escherichia coli associated with human diarrhoeal disease produce a class of pill represented by those called CS1, For the assembly of the major-pilin subunit, CooA, into pill, each of four linked genes, cooB,A,C, and D is required, In this study, we have determined the subcellular localization of CooB, C and D, and investigated the molecular interactions of these proteins using specific antisera, CooD appears to be an integral pilus protein because it co-purifies with, and is strongly associated with, CS1 pill, In keeping with its role as an assembly protein, the CooD minor pilin (when overexpressed in CS1-piliated strains) was detected in periplasmic intermolecular complexes with the major-pilin subunit CooA, CooB is an assembly protein found exclusively in the periplasm of CS1-piliated strains. CooB also forms periplasmic intermolecular complexes with CooA, but does not constitute part of the final pilus structure. Immunoblot analysis of cell fractions showed that CooC is an outer membrane protein of CS1-piliated E. coli, Based on this information, we have proposed a model for CS1-pilus assembly which is very similar to the model for polymerization of the PapA pilin of uropathogenic E. coli, As the assembly proteins of Pap and CS1 pill are structurally unrelated, this may represent a case of convergent evolution.