Structural basis for binding of accessory proteins by the appendage domain of GGAs
Structural basis for binding of accessory proteins by the appendage domain of GGAs
复制标题
GGA 附属结构域结合辅助蛋白的结构基础
DOI：
10.1038/nsb955
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发表时间：
2003
期刊：
影响因子：
--
通讯作者：
D. Owen
中科院分区：
文献类型：
--
作者：
B. Collins;Gerrit J. K. Praefcke;M. Robinson;D. Owen
高尔基相关、γ-适应素相关、adp -核糖基化因子结合蛋白（GGAs）和适应蛋白(AP)-1是参与网格蛋白介导的反式高尔基网络和内体系统之间转运的适应蛋白。GGAs的附属结构域和AP-1 γ-适应蛋白亚基在结构上是同源的，并通过与含有苯丙氨酸和酸性残基的短序列相互作用与附属蛋白结合。在这里，我们展示了人类GGA1附属物与p56附属蛋白的同源结合肽（DDDDFGGFEAAETFD）的结构，通过x射线晶体学确定。相互作用主要由肽的前两个苯丙氨酸残基与GGA1的保守碱性和疏水性残基的包装所控制。此外，几个主链氢键使肽在蛋白质先前存在的β-片的边缘形成额外的β-链。采用等温滴定量热法测定了不同多肽对GGA和γ-附件结构域的亲和力。
The Golgi-associated, γ-adaptin-related, ADP-ribosylation-factor binding proteins (GGAs) and adaptor protein (AP)-1 are adaptors involved in clathrin-mediated transport between the trans-Golgi network and endosomal system. The appendage domains of GGAs and the AP-1 γ-adaptin subunit are structurally homologous and have been proposed to bind to accessory proteins via interaction with short sequences containing phenylalanines and acidic residues. Here we present the structure of the human GGA1 appendage in complex with its cognate binding peptide from the p56 accessory protein (DDDDFGGFEAAETFD) as determined by X-ray crystallography. The interaction is governed predominantly by packing of the first two phenylalanine residues of the peptide with conserved basic and hydrophobic residues from GGA1. Additionally, several main chain hydrogen bonds cause the peptide to form an additional β-strand on the edge of the preexisting β-sheet of the protein. Isothermal titration calorimetry was used to assess the affinities of different peptides for the GGA and γ-appendage domains.