The structure of the Arabidopsis thaliana SOS3:: Molecular mechanism of sensing calcium for salt stress response
The structure of the Arabidopsis thaliana SOS3:: Molecular mechanism of sensing calcium for salt stress response
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DOI：
10.1016/j.jmb.2004.11.025
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发表时间：
2005-02-04
影响因子：
5.6
通讯作者：
Albert, A
中科院分区：
文献类型：
--
作者：
Sánchez-Barrena, MJ;Martínez-Ripoll, M;Albert, A
拟南芥（Arabidopsis thaliana）SOS3基因编码一种植物耐盐所需的钙传感器。SOS3蛋白结合并激活自抑制的SOS2蛋白激酶，其介导盐胁迫下对离子稳态重要的各种转运蛋白的表达和活性。SOS3属于一个独特的钙结合蛋白家族，包含两对EF手基序，具有四个推定的金属结合位点。我们报告的晶体结构的二聚体SOS 3蛋白质与钙，钙和锰的复合物。分析超离心实验和圆二色性测量表明，钙结合是负责二聚化的SOS 3。这导致蛋白质的整体形状和表面性质的变化，这可能足以传递盐胁迫期间引起的Ca2+信号。(C)2004 Elsevier Ltd.保留所有权利。
The Arabidopsis thaliana SOS3 gene encodes a calcium sensor that is required for plant salt tolerance. The SOS3 protein binds to and activates the self-inhibited SOS2 protein kinase, which mediates the expression and activities of various transporters important for ion homeostasis under salt stress. SOS3 belongs to a unique family of calcium-binding proteins that contain two pairs of EF hand motifs with four putative metal-binding sites. We report the crystal structure of a dimeric SOS3 protein in complex with calcium, and with calcium and manganese. Analytical ultracentrifugation experiments and circular dichroism measurements show that calcium binding is responsible for the dimerization of SOS3. This leads to a change in the global shape and surface properties of the protein that may be sufficient to transmit the Ca2+ signal elicited during salt stress. (C) 2004 Elsevier Ltd. All rights reserved.