A new essential protein kinase in Mycobacterium tuberculosis

 描述(由申请人提供) 磷信号在各个层面控制着结核分枝杆菌(Mtb)的生理和发病机制。除了使His和Asp上的蛋白磷酸化的双组分系统外，Mtb还产生11个丝氨酸/苏氨酸蛋白激酶(STPKs)。这些STPKs是细菌适应的中心，而两个Mtb STPKs，PKnA和PKnB，对于生长和作为药物靶点的开发是必不可少的。这11个STPKs是在1998年的Mtb基因组序列中发现的，自那以后就没有描述过新的STPKs。在Mtb ATPase的功能蛋白质组学筛选中，我们确定了&gt；80假设的蛋白质是以前未被识别的新的ATPase。进一步的表征表明，其中一个假说Rv0647c与非典型的STPKs具有远程结构同源性。鉴于Rv0647c的ATPase活性，我们对STPK活性进行了测试，发现Rv0647c是一种新的、高度分化的STPK。重要的是，Rv0647c被预测是必需的，这表明Rv0647c具有与结核分枝杆菌生长相关的核心功能。在这里，我们将通过测试Rv0647c的重要性、鉴定细胞底物和解决Rv0647c的晶体结构来验证Rv0647c是Mtb中的生长调节蛋白的假设。总而言之，该项目确定了Mtb磷酸信号网络的一个新组件，并为靶向高度可药物酶家族的这一成员提供了基础。

 DESCRIPTION (provided by applicant) Phosphosignaling controls Mycobacterium tuberculosis (Mtb) physiology and pathogenesis on every level. In addition to two-component systems that phosphorylate protein on His and Asp, Mtb also produces eleven Ser/Thr kinases (STPKs). These STPKs are central for bacterial adaptations, and two Mtb STPKs, PknA and PknB, are essential for growth and under development as drug targets. The eleven STPKs were identified in the 1998 Mtb genome sequence, and no new STPKs have been described since. In a functional proteomics screen of Mtb ATPases, we identified >80 hypothetical proteins as novel, previously unrecognized ATPases. Further characterization showed remote structural homology of one of the hypotheticals, Rv0647c, with non- typical STPKs. Given the ATPase activity of Rv0647c, we tested for STPK activity and found that Rv0647c is a novel, highly divergent STPK. Importantly, Rv0647c is predicted to be essential, suggesting that Rv0647c has central functions relating to Mtb growth. Here, we will test the hypothesis that Rv0647c is a growth regulator kinase in Mtb by testing Rv0647c's essentiality, identifying cellular substrates, and by solving the Rv0647c crystal structure. Together, this project identifies a new component of the Mtb phosphosignaling network and provides the basis for targeting this member of a highly druggable enzyme family.