Comprehensive analysis of OmpR phosphorylation, dimerization, and DNA binding supports a canonical model for activation.
Comprehensive analysis of OmpR phosphorylation, dimerization, and DNA binding supports a canonical model for activation.
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DOI：
10.1016/j.jmb.2013.02.003
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发表时间：
2013-05-27
影响因子：
5.6
通讯作者：
Stock, Ann M.
中科院分区：
文献类型：
--
作者：
Barbieri, Christopher M.;Wu, Ti;Stock, Ann M.
关键词：
OmpR/PhoB家族是最大的一类双组分系统（TCS）信号转导蛋白。这些转录因子的广泛的生物化学和结构表征提供了深入了解其激活和DNA结合机制。在大多数情况下，OmpR/PhoB家族蛋白被认为通过从其同源组氨酸激酶（HK）伴侣磷酸化而被激活，这反过来促进RR的变构变化，从而实现同源二聚化并随后增强DNA结合。不一致的是，有人认为，OmpR，该RR家族的epaR成员，通过不同的机制被激活，其中DNA结合在促进二聚化和磷酸化中起着核心作用。EnvZ/OmpR TCS激活后OmpR和OmpR DNA结合突变体磷酸化的速率和程度的表征表明，DNA结合对于体内OmpR的磷酸化并不是必需的。此外，详细分析的能量的DNA结合和二聚化的OmpR在其非磷酸化和磷酸化状态表明，磷酸化增强OmpR的二聚化，这种二聚化增强是充满活力的驱动力磷酸化介导的调节OmpR-DNA结合。这些发现表明，OmpR磷酸化介导的激活遵循与OmpR/PhoB家族的其他成员相同的模式，与以前提出的OmpR激活模型相反。
The OmpR/PhoB family of response regulators (RRs) is the largest class of two-component system (TCS) signal transduction proteins. Extensive biochemical and structural characterization of these transcription factors has provided insights into their activation and DNA-binding mechanisms. For the most part, OmpR/PhoB family proteins are thought to become activated through phosphorylation from their cognate histidine kinase (HK) partners, which in turn facilitates an allosteric change in the RR enabling homodimerization and subsequently enhanced DNA binding. Incongruently, it has been suggested that OmpR, the eponymous member of this RR family, becomes activated via different mechanisms, whereby DNA binding plays a central role in facilitating dimerization and phosphorylation. Characterization of the rate and extent of the phosphorylation of OmpR and OmpR DNA-binding mutants following activation of the EnvZ/OmpR TCS shows that DNA binding is not essential for phosphorylation of OmpR in vivo. In addition, detailed analyses of the energetics of DNA binding and dimerization of OmpR in both its unphosphorylated and phosphorylated state indicate that phosphorylation enhances OmpR dimerization and that this dimerization enhancement is the energetic driving force for phosphorylation-mediated regulation of OmpR-DNA binding. These findings suggest that OmpR phosphorylation mediated activation follows the same paradigm as the other members of the OmpR/PhoB family of RRs in contrast to previously proposed models of OmpR activation.
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DOI：
10.1073/pnas.94.7.2828
发表时间：
1997-04-01
影响因子：
11.1
作者：
Huang, KJ;Lan, CY;Igo, MM
通讯作者：
Igo, MM
影响因子：
3.6
作者：
Batchelor, E;Goulian, M
通讯作者：
Goulian, M
影响因子：
3.2
作者：
Klein, Adam H.;Shulla, Ana;Wolfe, Alan J.
通讯作者：
Wolfe, Alan J.
影响因子：
4.8
作者：
Cai, SJ;Inouye, M
通讯作者：
Inouye, M
影响因子：
5.4
作者：
Kenney, Linda J.
通讯作者：
Kenney, Linda J.