Structure of the response regulator RPA3017 involved in red-light signaling in Rhodopseudomonas palustris.
Structure of the response regulator RPA3017 involved in red-light signaling in Rhodopseudomonas palustris.
复制标题
沼泽红假单胞菌中参与红光信号传导的反应调节器 RPA3017 的结构。
DOI：
10.1107/s2053230x15014661
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Yang,Xiaojing
中科院分区：
文献类型：
--
作者：
Yang,Xuefei;Zeng,Xiaoli;Moffat,Keith;Yang,Xiaojing
双组分信号转导是细菌在复杂环境条件下生存和繁衍的主要信号机制。光合细菌沼泽假单胞菌利用两个串联的细菌光敏色素RpBphP2和RpBphP3来感知红光信号，调节弱光条件下捕光复合体的合成。RpBphP2和RpBphP3都是与相同的反应调节因子RPA3017偶联的光敏性组氨酸蛋白激酶。它们共同构成了一个将红灯信号转换为生物信号的双组分系统。在这项工作中，RPA3017的晶体结构是以非磷化形式给出的，其分辨率为1.9 ä。这种结构揭示了一种紧密相关的二聚体排列，这种排列在光敏色素相关的反应调节因子中是保守的。保守的活性中心结构为RpBphP2/RpBphP3和RPA3017之间的磷酸转移反应提供了结构信息。在结构比较和同源模型的基础上，进一步探讨了RpBphP2/RpBphP3和RPA3017之间如何在分子水平上实现特异性识别。
Two-component signal transduction is the major signaling mechanism that enables bacteria to survive and thrive in complex environmental conditions. The photosynthetic bacterium R. palustris employs two tandem bacteriophytochromes, RpBphP2 and RpBphP3, to perceive red-light signals that regulate the synthesis of light-harvesting complexes under low-light conditions. Both RpBphP2 and RpBphP3 are photosensory histidine kinases coupled to the same response regulator RPA3017. Together, they constitute a two-component system that converts a red-light signal into a biological signal. In this work, the crystal structure of RPA3017 in the unphosphorylated form at 1.9 Å resolution is presented. This structure reveals a tightly associated dimer arrangement that is conserved among phytochrome-related response regulators. The conserved active-site architecture provides structural insight into the phosphotransfer reaction between RpBphP2/RpBphP3 and RPA3017. Based on structural comparisons and homology modeling, how specific recognition between RpBphP2/RpBphP3 and RPA3017 is achieved at the molecular level is further explored.