Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD 20742, USA.
Curr Opin Microbiol. 2010 Apr;13(2):133-41. doi: 10.1016/j.mib.2009.12.013. Epub 2010 Jan 29.
Protein histidine kinases (PHKs) function in Two Component Signaling pathways utilized extensively by bacteria and archaea. Many PHKs participate in three distinct, but interrelated signaling reactions: autophoshorylation, phosphotransfer (to a partner Response Regulator (RR) protein), and dephosphorylation of this RR. Detailed biochemical and structural characterization of several PHKs has revealed how the domains of these proteins can interact to assemble the three active sites that promote the necessary chemistry and how these domain interactions might be regulated in response to sensory input: the relative orientation of helices in the PHK dimerization domain can reorient, via cogwheeling (rotation) and kinking (bending), to effect changes in PHK activities that probably involve sequestration/release of the PHK catalytic domain by the dimerization domain.
蛋白组氨酸激酶 (PHK) 在细菌和古菌广泛利用的双组分信号通路中发挥作用。许多 PHK 参与三个不同但相互关联的信号反应:自磷酸化、磷酸转移(到一个伙伴反应调节蛋白 (RR) 蛋白),以及 RR 的去磷酸化。对几种 PHK 的详细生化和结构特征分析揭示了这些蛋白质的结构域如何相互作用以组装促进必要化学的三个活性位点,以及这些结构域相互作用如何响应感应输入进行调节:PHK 二聚化结构域中螺旋的相对取向可以通过齿轮转动(旋转)和扭曲(弯曲)重新定向,从而改变 PHK 的活性,这可能涉及二聚化结构域对 PHK 催化结构域的隔离/释放。