Structural characterization of calcineurin B homologous protein 1
Structural characterization of calcineurin B homologous protein 1
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DOI：
10.1074/jbc.m503390200
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发表时间：
2005-09-16
影响因子：
4.8
通讯作者：
Shimizu, T
中科院分区：
文献类型：
--
作者：
Naoe, Y;Arita, K;Shimizu, T
钙调神经磷酸酶B同源蛋白1（CHP 1），也称为p22，是一种钙结合EF-手蛋白，在膜运输中发挥作用。它结合多种效应蛋白，包括Na+/H+交换剂、丝氨酸/苏氨酸激酶和钙调神经磷酸酶，可能调节其功能。已在2.2埃分辨率下测定了大鼠钙结合CHP 1的晶体结构。该分子具有紧凑的α-螺旋结构，包含四个EF-手。该蛋白的整体折叠拓扑结构与钙调神经磷酸酶的调节B亚基以及钙和整合素结合蛋白的折叠拓扑结构相似。钙离子以典型的方式配位在第三和第四EF-臂中，但第一和第二EF-臂不含钙离子。第一个EF手通过内部相互作用维持，第二个EF手通过疏水相互作用稳定。CHP 1在蛋白质的与EF-手相反的一侧上含有疏水口袋，其涉及配体结合。
Calcineurin B homologous protein 1( CHP1), also known as p22, is a calcium-binding EF-hand protein that plays a role in membrane trafficking. It binds to multiple effector proteins, including Na+/H+ exchangers, a serine/threonine kinase, and calcineurin, potentially modulating their function. The crystal structure of calcium-bound CHP1 from rat has been determined at 2.2 angstrom of resolution. The molecule has a compact alpha-helical structure containing four EF-hands. The overall folding topology of the protein is similar to that of the regulatory B subunit of calcineurin and to that of calcium-and integrin-binding protein. The calcium ion is coordinated in typical fashion in the third and fourth EF-hands, but the first and second EF-hands contain no calcium ion. The first EF-hand is maintained by internal interactions, and the second EF- hand is stabilized by hydrophobic interactions. CHP1 contains a hydrophobic pocket on the opposite side of the protein to the EF- hands that has been implicated in ligand binding.