STRUCTURAL STUDIES OF SIGNALING MOLECULES FROM M TUBERCULOSIS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 膜结合丝氨酸/苏氨酸蛋白激酶（STPKs）是结核病病原菌结核分枝杆菌（Mycobacterium tuberculosis）中调控途径的重要组成部分。 TB中存在9种单程跨膜激酶，这些旁系同源蛋白具有显著的序列同源性（30-60%），表明结构和机制保守。 对这些蛋白质的结构分析发现了与激酶活性的全局调节相关的重要事实，以及设计有区别的抑制剂的可能机制。 我们以前的晶体学模型的激酶结构域的PknE和PknB有牵连同源二聚化的激酶活性的变构调节的机制。 酶结构域的结构研究提供了线索的机制，二聚化，但包括一系列的配体结合和催化状态的模型是必要的二聚化和催化循环的完整理解。 此外，需要PknE的胞外结构域的结构来证明该结构域在二聚化和激酶调节中的功能。 我已经将PknE激酶结构域与结合的核苷酸和PknE传感器结构域结晶。 我请求SSRL的束时间来确定这些结构，这些结构有可能首次揭示细菌受体STPK的细胞内和细胞外结构域。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Membrane bound serine/threonine protein kinases (STPKs) are essential components of regulatory pathways in the pathogenic bacterium Mycobacterium tuberculosis, the causative agent of tuberculosis. Nine single-pass, transmembrane kinases are present in TB and these paralogous proteins share significant sequence homology (30-60%), indicating conservation of structure and mechanism. Structural analysis of these proteins is discovering important facts related to global regulation of kinase activity and possible mechanisms for the design of discriminating inhibitors. Our previous crystallographic models of kinase domains of PknE and PknB have implicated homodimerization as a mechanism for allosteric regulation of kinase activity. Structural studies of the enzymatic domains have provided clues towards the mechanism of dimerization, but models comprising a range of ligand-bound and catalytic states are necessary for complete understanding of dimerization and the catalytic cycle. Furthermore, the structure of the extracellular domain of PknE is required to demonstrate the function of this domain in dimerization and kinase regulation. I have crystallized the PknE kinase domain with bound nucleotide and the PknE sensor domain. I request beam time at SSRL to determine these structures which have the potential to reveal for the first time both the intracellular and extracellular domains of a bacterial receptor STPK.