ATPASE KINETICS AND MACROMOLECULAR ASSEMBLIES OF S54-DEPENDENT, AAA+ ATPASES

S54 依赖性 AAA ATP酶的ATP酶动力学和大分子组装

• 批准号: 8168613
• 负责人: B TRACY NIXON
• 金额: $ 3.24万
• 依托单位: ILLINOIS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8168613
• 关键词: ATP Hydrolysis; ATP phosphohydrolase; Address; Binding Sites; Cell division; Cells; Computer Retrieval of Information on Scientific Projects Database; DNA; Defect; Disease; Funding; Gene Expression; Genetic Transcription; Grant; Human; Hydrogen; Institution; Kinetics; Mechanics; Membrane; Molecular Machines; Nitrogen Fixation; Nucleotides; Organelles; Outcome; Phase; Production; Proteins; Research; Research Personnel; Resources; Source; Structure; United States National Institutes of Health; Work; enhancer binding protein; fascinate; macromolecular assembly; mutant; pathogen; remediation; repaired

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. Why do defects in molecular machines (AAA+ ATPases) cause disease? These protein machines convert ATP hydrolysis into mechanical work. Both human cells and disease causing pathogens use this work to physically manipulate proteins or DNA to dismantle and reassemble membranes or other organelles, to replicate DNA and traverse cell division, to repair damaged proteins, or to regulate gene expression. We do not know how these molecular machines convert ATP hydrolysis into mechanical work. Our research focuses on one subset of AAA+ ATPAses, the bacterial-enhancer-binding proteins (EBPs) which use their ATPase activities to regulate transcription of genes needed for harmful activites (diseases, crop damage) or helpful ones (nitrogen fixation, environmental remediation, hydrogen or other metabolite production). In prior projects, we established two mechanisms for regulating the EBP ATPases, defined structural changes occuring in their catalytic cycle, and are addressing the underlying mechanism via structure function studies of mutant forms of ATPase. A fascinating yet unexpected outcome was observed upon titrating ADP-BeFx and recording changes in the SAXS profile of the NtrC1 ATPase. Two distinct phases of conformational change were observed. The first involved reducing Rg from 47 ¿ to 42 ¿ as about half of the available nucleotide binding sites became occupied. The second phase, only occurring after the first transition was completed and additional nucleotide binding sites became occupied, involved change in the SAXS profile at higher Q values.

该子项目是利用该技术的众多研究子项目之一 资源由 NIH/NCRR 资助的中心拨款提供。子项目及 研究者 (PI) 可能已从 NIH 的另一个来源获得主要资金， 因此可以在其他 CRISP 条目中表示。列出的机构是 对于中心来说，它不一定是研究者的机构。 为什么分子机器（AAA+ ATP酶）的缺陷会导致疾病？这些蛋白质机器将 ATP 水解转化为机械功。人类细胞和致病病原体都利用这项工作来物理操纵蛋白质或 DNA，以拆卸和重新组装膜或其他细胞器、复制 DNA 和遍历细胞分裂、修复受损的蛋白质或调节基因表达。我们不知道这些分子机器如何将 ATP 水解转化为机械功。我们的研究重点是 AAA+ ATPA 酶的一个子集，即细菌增强子结合蛋白 (EBP)，它们利用 ATP 酶活性来调节有害活动（疾病、作物损害）或有益活动（固氮、环境修复、氢气或其他代谢物生产）所需的基因转录。 在之前的项目中，我们建立了两种调节 EBP ATP 酶的机制，定义了其催化循环中发生的结构变化，并通过 ATP 酶突变形式的结构功能研究来解决潜在的机制。在滴定 ADP-BeFx 并记录 NtrC1 ATP 酶 SAXS 谱的变化时，观察到了令人着迷但意想不到的结果。观察到构象变化的两个不同阶段。第一个涉及将 Rg 从 47 减少到 42，因为大约一半的可用核苷酸结合位点被占据。第二阶段仅在第一次转变完成且额外的核苷酸结合位点被占据后发生，涉及较高 Q 值下 SAXS 谱的变化。