The turn of the screw:: Variations of the abundant β-solenoid motif in passenger domains of Type V secretory proteins
The turn of the screw:: Variations of the abundant β-solenoid motif in passenger domains of Type V secretory proteins
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DOI：
10.1016/j.jsb.2006.01.015
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发表时间：
2006-08-01
影响因子：
3
通讯作者：
Steven, Alasdair C.
中科院分区：
文献类型：
--
作者：
Kajava, Andrey V.;Steven, Alasdair C.
革兰氏阴性菌的许多毒力因子是由V型分泌系统通过自转运蛋白（AT）和双配偶体分泌（TPS）途径分泌的。AT蛋白影响其自身的分泌。它们包括三个领域：氨基末端前导序列;分泌乘客结构域;和形成分泌通道的转运子结构域。在TPS途径中，乘客和转运域被翻译为单独的蛋白质。在以前的出版物中，我们提出了一个β-螺旋结构的TPS乘客域的丝状血凝素（FHA）的百日咳博德特氏菌，其中包含两个道，R1和R2，19个残基的序列重复，并建立了分子模型的R1和R2 β-螺旋。在这里，我们比较了R1的结构预测与最近确定的晶体结构的一个片段，包含三个R1重复，并找到密切的协议，与RMSD为1.1埃。在此期间，已知AT和TPS蛋白序列的数量增加到> 1000。为了研究它们中β-螺旋结构的发生率，我们进行了基于序列的分析，并得出结论，尽管乘客结构域的大小和序列存在很大差异，但它们中的大多数都含有β-螺旋，我们根据其β-螺旋的独特性质将其分为13种类型在2D螺旋模板中总结的序列（重复长度、β链和转角的数量和长度、横截面形状、特定位置中特定残基的存在）。一些螺旋类型对于常规AT蛋白是典型的，其他螺旋类型对于TPS或三聚体AT蛋白是典型的。一些β-微结构由具有不同类型线圈的堆叠子域组成。为了说明从线圈模板的模型构建，我们模拟了T4型β-螺线管TibA的大肠杆菌，预测有两个保守的极性残基，苏氨酸和谷氨酰胺，在内部位置。(c)2006年由Elsevier Inc.出版
Many virulence factors of gram-negative bacteria are secreted by the Type V secretion system via the autotransporter (AT) and two-partner secretion (TPS) pathways. AT proteins effect their own secretion. They comprise three domains: the amino-terminal leader sequence; the secreted passenger domain; and the translocator domain that forms the secretory channel. In the TPS pathway, the passenger and translocator domains are translated as separate proteins. In a previous publication, we proposed a beta-helical structure for the TPS passenger domain of the filamentous hemagglutinin (FHA) of Bordetella pertussis which contains two tracts, R1 and R2, of 19-residue sequence repeats and built molecular models for the R1 and R2 beta-helices. Here, we compare the structure predicted for R1 with the recently determined crystal structure of a fragment containing three R1 repeats and find close agreement, with an RMSD of 1.1 angstrom. In the interim, the number of known AT and TPS protein sequences has increased to > 1000. To investigate the incidence of beta-helical structures among them, we carried out a sequence-based analysis and conclude that, despite wide diversity in the sizes and sequences of passenger domains, most of them contain beta-solenoids that we classify into thirteen types based on distinctive properties of their beta-coils (repeat length, numbers and lengths of beta-strands and turns, cross-sectional shape, presence of specific residues in certain positions) summarized in a 2D coil template. Some coil types are typical for conventional AT proteins, others, for TPS or trimeric AT proteins. Some beta-solenoids consist of stacked subdomains with coils of different types. To illustrate model-building from a coil template, we modeled a type-T4 beta-solenoid for TibA of Escherichia coli which is predicted to have two conserved polar residues, Thr and Gln, in interior positions. (c) 2006 Published by Elsevier Inc.