Structure of the Mg(2+)-bound form of CheY and mechanism of phosphoryl transfer in bacterial chemotaxis.
Structure of the Mg(2+)-bound form of CheY and mechanism of phosphoryl transfer in bacterial chemotaxis.
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DOI：
10.1021/bi00212a001
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发表时间：
1994-04
期刊：
影响因子：
2.9
通讯作者：
Ann M Stock;E. Martinez-Hackert;B. Rasmussen;A. West;J. Stock;D. Ringe;G. Petsko
中科院分区：
文献类型：
--
作者：
Ann M Stock;E. Martinez-Hackert;B. Rasmussen;A. West;J. Stock;D. Ringe;G. Petsko
细菌趋化反应调节蛋白Chey是一大类信号转导蛋白的代表，其功能是作为磷酸化激活的开关来调节相关效应域的活性。这些调节剂催化金属离子依赖的磷酸化转移和去磷酸化反应，从而控制效应器的活性。本文测定了活性中心有镁离子结合和不有镁离子结合的鼠伤寒沙门氏菌Chey的晶体结构，并在1.8A分辨率下进行了精炼。虽然金属结合和非金属结合的Chey的整体结构相似，但在活性部位发生了重大的重排，涉及反应调节家族中三个最保守的残基。反应调节结构域活性部位的羧酸侧链簇的保守可以根据它们在协调催化必需的二价金属离子方面的作用而合理化。镁离子的配位几何构型为磷酰化转移的机理提供了理论依据。
The response regulator protein of bacterial chemotaxis, CheY, is representative of a large family of signal transduction proteins that function as phosphorylation-activated switches to regulate the activities of associated effector domains. These regulators catalyze the metal ion-dependent phosphoryl transfer and dephosphorylation reactions that control the effector activities. The crystal structures of Salmonella typhimurium CheY with and without Mg2+ bound at the active site have been determined and refined at 1.8-A resolution. While the overall structures of metal-bound and metal-free CheY are similar, significant rearrangements occur within the active site involving the three most highly conserved residues of the response regulator family. Conservation of the cluster of carboxylate side chains at the active site of response regulator domains can be rationalized in terms of their role in coordinating the catalytically essential divalent metal ion. The Mg2+ coordination geometry provides insights to the mechanism of phosphoryl transfer.