Structural Analysis of Sensor Domains from the TMAO-Responsive Histidine Kinase Receptor TorS
Structural Analysis of Sensor Domains from the TMAO-Responsive Histidine Kinase Receptor TorS
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DOI：
10.1016/j.str.2009.07.015
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发表时间：
2009-09-09
期刊：
影响因子：
5.7
通讯作者：
Hendrickson, Wayne A.
中科院分区：
文献类型：
--
作者：
Moore, Jason O.;Hendrickson, Wayne A.
在所有原核生物和某些真核生物中，组氨酸激酶受体对多种信号作出反应并介导跨质膜的信号转导。每个受体都是调节特定细胞过程的双组分系统的一部分。使用三甲胺 N-氧化物 (TMAO) 作为末端电子受体的生物体通常通过 TMAO 还原酶 (Tor) 途径控制其无氧呼吸，TorS 组氨酸激酶在检测到环境中的 TMAO 时会激活该途径。我们已经确定了大肠杆菌和副溶血弧菌 TorS 受体周质传感器结构域的晶体结构。 TorS 传感器域具有一种新颖的折叠，由膜近端右手四螺旋束和膜远端左手四螺旋束组成，但这两种结构的构象配置存在显着差异。孤立的 TorS 传感器域在解决方案中二聚化；通过与二聚体 NarX 和 Tar 传感器的比较，我们假设通过 TorS 二聚体发出的信号涉及螺旋之间的活塞型位移。
Histidine kinase receptors respond to diverse signals and mediate signal transduction across the plasma membrane in all prokaryotes and certain eukaryotes. Each receptor is part of a two-component system that regulates a particular cellular process. Organisms that use trimethylamine-N-oxide (TMAO) as a terminal electron acceptor typically control their anaerobic respiration through the TMAO reductase (Tor) pathway, which the TorS histidine kinase activates when sensing TMAO in the environment. We have determined crystal structures for the periplasmic sensor domains of TorS receptors from Escherichia coli and Vibrio parahaemolyticus. TorS sensor domains have a novel fold consisting of a membrane-proximal right-handed four-helical bundle and a membrane-distall left-handed four-helical bundle, but conformational dispositions differ significantly in the two structures. Isolated TorS sensor domains dimerize in solution; and from comparisons with dimeric NarX and Tar sensors, we postulate that signaling through TorS dimers involves a piston-type displacement between helices.