Regulation of (p)ppGpp-metabolic activities of RelA, Rel and SpoT

RelA、Rel 和 SpoT 的 (p)ppGpp 代谢活性的调节

• 批准号: 314783864
• 负责人: Professor Dr. Gert Bange
• 金额: --
• 依托单位: Zentrum für Synthetische Mikrobiologie (SYNMIKRO)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/314783864?language=en
• 关键词: Regulation; ppGpp; metabolic; activities; RelA

The stringent response is a central bacterial adaptation mechanism, which plays an important role in regulation of bacterial virulence, survival during host invasion, antibiotic resistance and persistence. In response to various stress stimuli, the stringent response protein RelA modulates the intracellular concentration of the alarmone nucleotides (p)ppGpp. RelA possesses a strong ribosome-dependent (p)ppGpp synthetic activity that is activated by amino acid starvation via direct sensing of the deacylated tRNA in the ribosomal A-site. The paucity of our understanding of the structural aspects of the mechanism of key RelA and other stringent response proteins is hampering the progress of the SR field itself as well as the development of efficient molecular tools for controlling the SR. We plan to address this void by determination of X-ray structures of RelA alone and in complex with substrates as well as determine cryo-electron microscopy structures of RelA in complex with the bacterial ribosome. Moreover, we will provide a kinetic description of the interplay of the RelA hydrolase and synthetase functions during the stringent response. Collectively our findings will provide fundamental and mechanistic in the process by which RelA mediates the stringent response via production of (p)ppGpp. Moreover, our findings will also provide a structural basis for the design of novel antimicrobial agents to combat the ever-increasing prevalence of multi-drug resistant pathogenic bacteria.

严格反应是细菌的核心适应机制，在调节细菌毒力、宿主入侵生存、抗生素耐药性和持久性等方面发挥着重要作用。在对各种应激刺激的反应中，严格反应蛋白RelA调节警报酮核苷酸(p)ppGpp的细胞内浓度。RelA具有很强的核糖体依赖(p)ppGpp合成活性，通过直接感知核糖体a位点的去乙酰化tRNA，通过氨基酸饥饿激活。我们对关键RelA和其他严格响应蛋白的结构机制的理解不足，阻碍了SR领域本身的进展，也阻碍了有效分子工具的发展，以控制SR。我们计划通过测定RelA单独和与底物复合物的x射线结构，以及测定RelA与细菌核糖体复合物的冷冻电镜结构来解决这一空白。此外，我们将提供RelA水解酶和合成酶功能在严格响应过程中相互作用的动力学描述。总的来说，我们的研究结果将为RelA通过产生(p)ppGpp介导严格反应的过程提供基础和机制。此外，我们的研究结果还将为设计新型抗菌药物提供结构基础，以对抗日益流行的多重耐药致病菌。