Structure of the tetraspanin main extracellular domain -: A partially conserved fold with a structurally variable domain insertion
Structure of the tetraspanin main extracellular domain -: A partially conserved fold with a structurally variable domain insertion
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DOI：
10.1074/jbc.m105557200
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发表时间：
2001-10-26
影响因子：
4.8
通讯作者：
Conjeaud, H
中科院分区：
文献类型：
--
作者：
Seigneuret, M;Delaguillaumie, A;Conjeaud, H
膜糖蛋白的四跨膜蛋白家族参与细胞发育、增殖、活化和移动性的调节。我们试图预测四跨膜蛋白（EC2）的大胞外结构域的结构特征，这是非常重要的，在确定其功能特异性。四跨膜蛋白EC2由两个亚结构域组成：保守的三螺旋亚结构域和插入保守亚结构域内的可变二级结构亚结构域。关键的二硫桥和其他不变的残基的发生导致一个保守的相对拓扑结构的两个子域，也表明四跨膜蛋白的结构分类。使用CD 81 EC2结构作为模板，通过同源性建模预测另外两个EC2的结构，并指示保守的形状，其中可变亚结构域位于结构的一侧。保守的和可变的亚结构域可能包含的网站，分别对应于常见的和特定的相互作用的四跨膜蛋白。四跨膜蛋白EC2似乎对应于蛋白质之间的折叠保守性/可变性的新方案，即在保守折叠内插入结构可变的亚结构域。
The tetraspanin family of membrane glycoproteins is involved in the regulation of cellular development, proliferation, activation, and mobility. We have attempted to predict the structural features of the large extracellular domain of tetraspanins (EC2), which is very important in determining their functional specificity. The tetraspanin EC2 is composed of two subdomains: a conserved three-helix subdomain and a variable secondary structure subdomain inserted within the conserved subdomain. The occurrence of key disulphide bridges and other invariant residues leads to a conserved relative topology of both subdomains and also suggests a structural classification of tetraspanins. Using the CD81 EC2 structure as a template, the structures of two other EC2s were predicted by homology modeling and indicate a conserved shape, in which the variable subdomain is located at one side of the structure. The conserved and variable subdomains might contain sites that correspond, respectively, to common and specific interactions of tetraspanins. The tetraspanin EC2 seems to correspond to a new scheme of fold conservation/variability among proteins, namely the insertion of a structurally variable subdomain within an otherwise conserved fold.