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.

该副本是使用众多研究子项目之一 由NIH/NCRR资助的中心赠款提供的资源。子弹和 调查员（PI）可能已经从其他NIH来源获得了主要资金， 因此可以在其他清晰的条目中代表。列出的机构是 对于中心，这是调查员的机构。 为什么分子机器（AAA+ ATPases）的缺陷会导致疾病？这些蛋白质机器将ATP水解转化为机械工作。引起病原体的人类细胞和疾病都使用这项工作来物理操纵蛋白质或DNA来拆除并重新组装膜或其他细胞器，以复制DNA和遍及细胞分裂，以修复受损的蛋白质，或调节基因表达。我们不知道这些分子机器如何将ATP水解转化为机械工作。我们的研究重点是AAA+ ATPases的一个子集，细菌 - 增强剂结合蛋白（EBP），这些蛋白（EBP）使用其ATPase活动来调节有害活动所需的基因转录（疾病，作物损害）或有帮助的基因（氮气固定，环境修复，氢化，氢或其他代谢物）。 在先前的项目中，我们建立了确定EBP ATPases的两种机制，定义了在催化周期中发生的结构变化，并通过ATPase突变形式的结构功能研究来解决基本机制。在滴定ADP-BEFX并记录NTRC1 ATPase的SAXS轮廓变化时，观察到了令人着迷但出乎意料的结果。观察到构象变化的两个不同阶段。第一个涉及将RG从47»降低到42�，因为大约一半的可用核苷酸结合位点被占据。第二阶段仅在第一个过渡完成并占据额外的核苷酸结合位点后才发生，涉及较高Q值的SAXS轮廓的变化。