Structural analysis and solution studies of the activated regulatory domain of the response regulator ArcA: a symmetric dimer mediated by the alpha4-beta5-alpha5 face.
Structural analysis and solution studies of the activated regulatory domain of the response regulator ArcA: a symmetric dimer mediated by the alpha4-beta5-alpha5 face.
复制标题
响应调节器 ArcA 的激活调节域的结构分析和解决方案研究：由 alpha4-beta5-alpha5 面介导的对称二聚体。
DOI：
10.1016/j.jmb.2005.03.059
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发表时间：
2005
影响因子：
5.6
通讯作者：
Stock,AnnM
中科院分区：
文献类型：
--
作者：
Toro-Roman,Alejandro;Mack,TimothyR;Stock,AnnM
Escherichia coli react to changes from aerobic to anaerobic conditions of growth using the ArcA-ArcB two-component signal transduction system. This system, in conjunction with other proteins, regulates the respiratory metabolic pathways in the organism. ArcA is a member of the OmpR/PhoB subfamily of response regulator transcription factors that are known to regulate transcription by binding in tandem to target DNA direct repeats. It is still unclear in this subfamily how activation by phosphorylation of the regulatory domain of response regulators stimulates DNA binding by the effector domain and how dimerization and domain orientation, as well as intra- and intermolecular interactions, affect this process. In order to address these questions we have solved the crystal structures of the regulatory domain of ArcA in the presence and absence of the phosphoryl analog, BeF3−. In the crystal structures, the regulatory domain of ArcA forms a symmetric dimer mediated by the α4-β5-α5 face of the protein and involving a number of residues that are highly conserved in the OmpR/PhoB subfamily. It is hypothesized that members of this subfamily use a common mechanism of regulation by dimerization. Additional biophysical studies were employed to probe the oligomerization state of ArcA, as well as its individual domains, in solution. The solution studies show the propensity of the individual domains to associate into oligomers larger than the dimer observed for the intact protein, and suggest that the C-terminal DNA-binding domain also plays a role in oligomerization.
