Solution Structure of Human ζ-COP: Direct Evidences for Structural Similarity between COP I and Clathrin-Adaptor Coats
Solution Structure of Human ζ-COP: Direct Evidences for Structural Similarity between COP I and Clathrin-Adaptor Coats
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DOI：
10.1016/j.jmb.2008.12.083
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发表时间：
2009-03-06
影响因子：
5.6
通讯作者：
Xia, Bin
中科院分区：
文献类型：
--
作者：
Yu, Wenyu;Lin, Jian;Xia, Bin
COP-T 包被的囊泡是蛋白质和脂质载体，介导高尔基体内运输以及从顺式高尔基体复合体到细胞内质网的运输。囊泡外壳的外壳由七个亚基组成：α-COP、ε-COP、β'-COP、β-COP、γ-COP、δ-COP 和 zeta-COP。在这里，我们报告了人类 zeta-COP（总共 177 个残基）的截短形式（残基 1-149；zeta-COP149）的溶液结构。这是第一个三维结构。 COP I F-子复合体的“核心”亚基的一部分。 zeta-COP149的结构主要由无序的N末端尾部、五链反平行β-折叠、两链反平行β-折叠和五个a-螺旋组成。 zeta-COP149的整体折叠与API-sigma 1和AP2-sigma 2的晶体结构非常相似，直接证明了COP I F子复合物的“核心”亚基与衔接蛋白复合物之间的结构相似性。通过结构比较和诱变研究，我们还证明zeta-COP149和gamma-COP异二聚体具有与AP2-sigma 2和AP2-α异二聚体相似的包装界面和相对亚基方向。这些结果提供了支持先前提议的直接证据，即 COP I F-亚复合物和接头蛋白复合物具有相似的三级和四级结构。 (C) 2009 Elsevier Ltd. 保留所有权利。
COP-T-coated vesicles are protein and lipid carriers that mediate intra-Golgi transport and transport from the cis-Golgi complex to the endoplasmic reticulum in cells. The coatomer of the vesicles coat is comprised of seven subunits: alpha-COP, epsilon-COP, beta'-COP, beta-COP, gamma-COP, delta-COP, and zeta-COP. Here we report the solution structure of a truncated form (residues 1-149; zeta-COP149) of human zeta-COP (total 177 residues). It is the first three-dimensional structure. of a "core" subunit of the COP I F-subcomplex. The structure of zeta-COP149 mainly consists of a disordered N-terminal tail, a five-stranded antiparallel beta-sheet, a two-stranded antiparallel beta-sheet, and five a-helices. The global folding of zeta-COP149 is very similar to the crystal structures of API-sigma 1 and AP2-sigma 2, directly demonstrating the structural similarity between the "core" subunits of the COP I F-subcomplex and adaptor protein complexes. Through structural comparison and mutagenesis study, we have also demonstrated that the heterodimers of zeta-COP149 and gamma-COP have packing interfaces and relative subunit orientations similar to those of AP2-sigma 2 and AP2-alpha heterodimers. These results provide direct evidence supporting the previous proposal that the COP I F-subcomplex and adaptor protein complexes have similar tertiary and quaternary structures. (C) 2009 Elsevier Ltd. All rights reserved.