Mechanism of Transcription Termination Protein RHO

转录终止蛋白RHO的机制

• 批准号: 8806747
• 负责人: Barbara Stitt
• 金额: $ 16.76万
• 依托单位: New York University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-08-01 至 1991-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8806747&HistoricalAwards=false
• 关键词: Mechanism; Transcription; Termination; Protein; RHO

Transcription termination protein rho of E. coli acts to release newly synthesized RNA from the DNA template and from paused RNA polymerase. Rho is an ATPase which is active only when RNA is bound, and rho must hydrolyze ATP to achieve transcript release. The mechanism of RNA-dependent nucleotide hydrolysis and the role of such hydrolysis in transcript release are not known. The goal of the present research is to understand both chemical and kinetic features of ATP binding, RNA binding, and ATP hydrolysis by rho and to apply this knowledge toward an understanding of the molecular mechanism of transcript release. The proposed experiments are concerned with (1) the stoichiometry, rates, and order of events on the enzyme: how many molecules of ligand bind, how fast, and in what order; (2) the overall reaction stoichiometry: how many molecules of ATP are hydrolyzed per RNA chain released; and (3) the molecular details of interactions between the enzyme and its substrates: what are the interactions by which the substrates bind, and what amino acid residues are important in catalysis? These experiments test specific models of rho action, which will either be supported or discarded based on the results. Aspects of this work will contribute to the understanding of other proteins that bind ATP or RNA and to the more general problem of biological energy transduction. This investigator is studying the process by which proteins are synthesized by the process of translation from messenger RNA. The last step in this process is the so-called termination step in which the completed protein chain is released from the RNA. This is a step which requires energy in the form of ATP. Dr. Stitt wishes to elucidate the mechanism by which this complex reaction takes place.

E.大肠杆菌的作用是 从DNA模板释放新合成的RNA， 暂停的RNA聚合酶。 Rho是一种ATP酶， 当RNA被结合时，rho必须水解ATP才能实现 成绩单释放。 RNA依赖性核苷酸的作用机制 水解和这种水解在转录物中的作用 释放是未知的。 本研究的目的是 了解ATP结合的化学和动力学特征， RNA结合和ATP被rho水解， 了解分子机制的知识， 成绩单释放。 建议的实验涉及（1） 化学计量，速率和酶的事件顺序：如何 许多配体分子结合，结合的速度和顺序; (2)整个反应的化学计量：有多少分子 每释放一条RNA链，ATP被水解;以及（3） 酶与其分子之间相互作用的分子细节 底物：底物通过什么相互作用 结合，以及哪些氨基酸残基在催化中是重要的？ 这些实验测试rho作用的特定模型， 将根据结果被支持或丢弃。 这项工作的各个方面将有助于了解 其他结合ATP或RNA的蛋白质， 生物能量转换的问题。 这位研究人员正在研究蛋白质在 通过翻译信使RNA合成的。 这个过程的最后一步是所谓的终止步骤 其中完整的蛋白质链从RNA中释放出来。 这是一个需要以ATP形式提供能量的步骤。 博士 斯蒂特希望阐明这种复合物 反应发生了。