Dissection of the sensor domain of the copper-responsive histidine kinase CorS from Myxococcus xanthus
Dissection of the sensor domain of the copper-responsive histidine kinase CorS from Myxococcus xanthus
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DOI：
10.1111/1758-2229.12389
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发表时间：
2016-06-01
影响因子：
3.3
通讯作者：
Munoz-Dorado, Jose
中科院分区：
文献类型：
--
作者：
Celestina Sanchez-Sutil, Maria;Javier Marcos-Torres, Francisco;Munoz-Dorado, Jose
粘球菌Xanthus CorSR是一个双组分系统，负责维持这种细菌对铜的反应。在这种金属的存在下，它上调，除其他外，编码多铜氧化酶CuoA和P-1B-ATP酶CopA的基因。组氨酸激酶CorS的周质传感器结构域的一系列的框内缺失突变体中产生的蛋白质的这一部分的分析的解剖已经揭示，铜传感需要在N末端的28个残基的区域和在C末端的9个残基的另一个区域。His 34、His 38和His 171处的点突变表明它们对于CorS感测铜的能力是必不可少的。此外，细菌双杂交系统的使用揭示了CorS单体之间的二聚化，即使在没有任何金属的情况下，并且铜增强了这种相互作用。当用在三个必需His残基处突变的蛋白质测试二聚化时，观察到这些蛋白质在不存在金属的情况下保持固有的二聚化能力。与野生型蛋白相反，铜没有加强相互作用，证实了铜与CorS的三个His残基结合是增强二聚化和传递信号所必需的。
Myxococcus xanthus CorSR is a two-component system responsible for maintaining the response of this bacterium to copper. In the presence of this metal it upregulates, among others, the genes encoding the multicopper oxidase CuoA and the P-1B-ATPase CopA. Dissection of the periplasmic sensor domain of the histidine kinase CorS by the analysis of a series of in-frame deletion mutants generated in this portion of the protein has revealed that copper sensing requires a region of 28 residues in the N terminus and another region of nine residues in the C terminus. Point mutations at His34, His38 and His171 demonstrate that they are essential for the ability of CorS to sense copper. Furthermore, the use of a bacterial two-hybrid system has revealed dimerization between monomers of CorS even in the absence of any metal, and that copper enhances this interaction. When dimerization was tested with proteins mutated at the three essential His residues, it was observed that these proteins maintain the intrinsic dimerization ability in the absence of metal. In contrast to the wild-type protein, copper did not strengthen the interaction, corroborating that copper binding to the three His residues of CorS is required for enhancing dimerization and transmitting the signal.