Rapid dephosphorylation of the TorR response regulator by the TorS unorthodox sensor in Escherichia coli
Rapid dephosphorylation of the TorR response regulator by the TorS unorthodox sensor in Escherichia coli
复制标题
DOI：
10.1128/jb.183.8.2691-2695.2001
复制
发表时间：
2001-04-01
影响因子：
3.2
通讯作者：
Méjean, V
中科院分区：
文献类型：
--
作者：
Ansaldi, M;Jourlin-Castelli, C;Méjean, V
torCAD操纵子的诱导，编码三甲胺N-氧化物（TMAO）呼吸系统，是由TorS-TorR磷酸化系统响应TMAO的可用性严格控制。TorS是一种非正统的传感器，它含有三个磷酸化位点，并通过四步磷酸化途径（His 443--> Asp 723--> His 850-->Asp（TorR））转磷酸化TorR。在这项研究中，我们提供的遗传证据表明，当TMAO被删除时，TorS可以去磷酸化TorR。去磷酸化可能通过反向磷酸化途径发生，即Asp（TorR）--> His 850--> Asp 723，因为His 850和Asp 723在此过程中都是必需的。通过使用逆转录酶PCR，我们还表明，TMAO去除结果在关闭的TOR操纵子转录在不到2分钟。根据我们的研究结果和类比其他磷酸化信号转导系统，我们建议，反向磷酸转移可能是一个快速，有效的机制，以抑制反应调节。
Induction of the torCAD operon, encoding the trimethylamine N-oxide (TMAO) respiratory system, is tightly controlled by the TorS-TorR phosphorelay system in response to TMAO availability. TorS is an unorthodox sensor that contains three phosphorylation sites and transphosphorylates TorR via a four-step phosphorelay, His443-->Asp723-->His850-->Asp(TorR). In this study, we provide genetic evidence that TorS can dephosphorylate phospho-TorR when TMAO is removed. Dephosphorylation probably occurs by a reverse phosphorelay, Asp(TorR)-->His850-->Asp723, since His850 and Asp723 are both essential in this process. By using reverse transcriptase PCR, we also show that TMAO removal results in shutoff of tor operon transcription in less than 2 min. Based on our results and on analogy to other phosphorelay signal transduction systems, we propose that reverse phosphotransfer could be a rapid and efficient mechanism to inactivate response regulators.