Structural and functional characterization of partner switching regulating the environmental stress response in Bacillus subtilis
Structural and functional characterization of partner switching regulating the environmental stress response in Bacillus subtilis
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DOI：
10.1074/jbc.m609733200
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发表时间：
2007-04-13
影响因子：
4.8
通讯作者：
Lewis, Richard J.
中科院分区：
文献类型：
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作者：
Hardwick, Steven W.;Pane-Farre, Jan;Lewis, Richard J.
枯草芽孢杆菌及其近亲的一般应激反应为细胞提供了免受各种应激的保护。环境应激信号转导级联的上游组分被RsbT激酶激活，所述RsbT激酶将结合伴侣从25 S大分子复合物（应激体）切换到RsbU磷酸酶。一旦RsbU磷酸酶通过与RsbT相互作用而被激活，替代性σ因子σ（B）指导一般应激调节子的转录。先前，我们证明了RsbU的N-末端结构域介导RsbT的结合。我们现在描述的残基N-RsbU是至关重要的这种相互作用的实验在体外和体内。此外，N-RsbU突变体的晶体结构为相互作用的丧失提供了分子解释。最后，我们还表征了RsbT中影响与RsbU和应激体的简化二元模型结合的突变体，从而鉴定了RsbT“开关上的重叠结合表面。".
The general stress response of Bacillus subtilis and close relatives provides the cell with protection from a variety of stresses. The upstream component of the environmental stress signal transduction cascade is activated by the RsbT kinase that switches binding partners from a 25 S macromolecular complex, the stressosome, to the RsbU phosphatase. Once the RsbU phosphatase is activated by interacting with RsbT, the alternative sigma factor, sigma(B), directs transcription of the general stress regulon. Previously, we demonstrated that the N-terminal domain of RsbU mediates the binding of RsbT. We now describe residues in N-RsbU that are crucial to this interaction by experimentation both in vitro and in vivo. Furthermore, crystal structures of the N-RsbU mutants provide a molecular explanation for the loss of interaction. Finally, we also characterize mutants in RsbT that affect binding to both RsbU and a simplified, binary model of the stressosome and thus identify overlapping binding surfaces on the RsbT "switch.".