Structure and Relations of Proteins and Nucleic Acids

蛋白质和核酸的结构和关系

• 批准号: 6622030
• 负责人: PETER H VON HIPPEL
• 金额: $ 33.59万
• 依托单位: UNIVERSITY OF OREGON
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-01-01 至 2005-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6622030
• 关键词: DNA directed RNA polymerase; Escherichia coli; bacterial RNA; bacterial genetics; bacterial proteins; bacteriophage lambda; chemical kinetics; computer simulation; fluorescent dye /probe; gene expression; host organism interaction; intermolecular interaction; model design /development; molecular assembly /self assembly; molecular site; nucleic acid structure; physical model; posttranscriptional RNA processing; protein structure function; stop flow technique; thermodynamics; transcription factor; transcription termination; virus genetics; virus protein

In this grant application we describe plans to continue our ongoing studies of the molecular mechanisms and regulation of the transcription complex of E. coli. We will focus, in particular, on how the complex is regulated by transcription factors, building on the recent major progress that has greatly increased our understanding both of many aspects of the structure of the complex, as well as of the thermodynamics and kinetics of the control of the reactions that lead to transcript initiation, elongation, editing, and termination. This later progress, in particular, makes it possible for us to begin to develop quantitative insight into the changes that the binding of transcription factors must bring about to (e.g.) redirect the transcription process from elongation to transcript editing or termination. During the next reporting period our Specific Aims will be: (i) to continue our studies of the mechanisms whereby the N protein-dependent antitermination system of phage lambda controls the transcription termination efficiency of E. coli RNA polymerase at intrinsic and rho-dependent terminators; (ii) to carry out fundamental studies of RNA flexibility and looping as a component of transcription regulation; (iii) to elucidate the role of specific RNA sequences and E. coli host factors in regulating the "range" and specificity of "full" transcription factor complexes involved in N-dependent antitermination; (iv) to determine the detailed mechanism of action of E. coli transcription termination factor rho at rho-dependent terminators, and to study the roles of "coupling factors" in regulating the efficiency of the rho-dependent termination process; (v) to examine the interconversion of the various forms of the E. coli transcription elongation complex that lead, respectively, to elongation, editing, and termination, as well as to use rho as a probe of these "functional states"; and (vi) to perform theoretical and modeling studies of the assembly and stability of functional complexes of transcription factors to better understand how these complexes assemble, and how the components interact to build a stable "macromolecular machine". In terms of their significance for biomedical research, these studies will serve as molecular models for the function and control of the analogous DNA-dependent RNA transcription systems of higher organisms, and may help reveal how these controls can go awry in cancer and other diseases of inappropriate gene expression.

在此赠款应用中，我们描述了继续我们对大肠杆菌转录复合物的分子机制和调节的持续研究的计划。 我们将特别关注复合物如何受转录因子的调节，这是建立在最近的主要进步上，这大大提高了我们的理解，这在复合体结构以及热力学和动力学方面的许多方面都大大提高了对反应的控制，这些反应导致转录引发，延长，编辑，剪辑，终止和终止。 尤其是后来的进展使我们有可能开始对转录因子的结合必须带来的变化（例如）将转录过程从伸长到转录本编辑或终止的变化进行定量见解。 在下一个报告期间，我们的具体目的是：（i）继续我们对噬菌体lambda的N蛋白依赖性抗通过抗灭菌系统的研究，控制了内在和Rho依赖性终端的大肠杆菌RNA聚合酶的转录终止效率； （ii）进行RNA柔韧性和循环的基本研究，作为转录调节的组成部分； （iii）阐明了特定的RNA序列和大肠杆菌宿主因子在调节N依赖性抗性涉及的“完整”转录因子复合物的“范围”和特异性中的作用； （iv）确定大肠杆菌转录终止因子Rho在Rho依赖性终结剂中的详细作用机理，并研究“耦合因子”在调节Rho依赖性终止过程效率方面的作用； （v）检查分别导致伸长，编辑和终止的各种形式的各种形式的大肠杆菌转录伸长复合物的相互转换，并使用RHO作为对这些“功能状态”的探测； （vi）对转录因子功能复合物的组装和稳定性进行理论和建模研究，以更好地了解这些复合物的组装方式，以及组件如何相互作用以构建稳定的“大分子机器”。就其对生物医学研究的重要性而言，这些研究将作为较高生物体的类似DNA依赖性RNA转录系统的功能和控制的分子模型，并可能有助于揭示这些控制在癌症和其他不合适基因表达的疾病中如何出现。