Role of unusual P loop ejection and autophosphorylation in HipA-mediated persistence and multidrug tolerance.
Role of unusual P loop ejection and autophosphorylation in HipA-mediated persistence and multidrug tolerance.
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DOI：
10.1016/j.celrep.2012.08.013
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发表时间：
2012-09-27
期刊：
影响因子：
8.8
通讯作者：
Brennan RG
中科院分区：
文献类型：
--
作者：
Schumacher MA;Min J;Link TM;Guan Z;Xu W;Ahn YH;Soderblom EJ;Kurie JM;Evdokimov A;Moseley MA;Lewis K;Brennan RG
HIPA是一种细菌丝氨酸/苏氨酸蛋白激酶，可磷酸化靶标以影响持久性和多药耐受。HIPA是残基的自动磷酸化，Ser150是HipA功能的关键调节机制。耐人寻味的是，Ser150不像其他激酶那样位于激活环上，而是位于蛋白质核心，在那里它形成了与ATP结合的“P-loop基序”的一部分。这种被掩埋的残基是如何被磷酸化并调节激酶活性的，目前尚不清楚。在这里，我们报告了多个结构，揭示了P-环基序表现出显著的“输入-输出”构象平衡，这允许进入Ser150及其分子间自动磷酸化。磷酸化的Ser150稳定“外状态”，通过破坏三磷酸腺苷结合口袋来使激酶失活。因此，我们的数据揭示了一种迄今未知的蛋白激酶调节机制，该机制对多药耐受和持久性至关重要，因为激酶失活提供了关键的第一步，使休眠细胞恢复生长表型并再次感染宿主。
HipA is a bacterial serine/threonine protein kinase that phosphorylates targets to effect persistence and multidrug tolerance. HipA is Autophosphorylation of residue Ser150 is a critical regulatory mechanism of HipA function. Intriguingly, Ser150 is not located on the activation loop as in other kinases but in the protein core where it forms part of the ATP-binding “P-loop motif”. How this buried residue is phosphorylated and regulates kinase activity is unclear. Here we report multiple structures revealing that the P-loop motif exhibits a remarkable “in-out” conformational equilibrium, which allows access to Ser150 and its intermolecular autophosphorylation. Phosphorylated Ser150 stabilizes the “out-state”, which inactivates the kinase by disrupting the ATP binding pocket. Thus, our data reveal a heretofore-unseen mechanism of protein kinase regulation that is vital for multidrug tolerance and persistence as kinase inactivation provides the critical first step to allow dormant cells to revert to the growth phenotype and to reinfect the host.