GENE CONTROL IN INFECTION AND LYSOGENY BY PHAGE LAMBDA

噬菌体 Lambda 对感染和溶原的基因控制

• 批准号: 2331947
• 负责人: JEFFREY W ROBERTS
• 金额: $ 37.92万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-02-01 至 1999-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2331947
• 关键词: DNA binding protein; DNA directed RNA polymerase; DNA footprinting; bacteriophage lambda; biological signal transduction; crosslink; gel mobility shift assay; gene expression; gene mutation; genetic library; genetic promoter element; genetic regulation; host organism interaction; hybrid cells; intermolecular interaction; lysogeny; molecular site; protein structure function; transcription factor; transcription termination; virus infection mechanism; virus protein

Our objective is to understand how RNA polymerase of E. coli is modified by the transcription antiterminator encoded by the phage lambda gene Q. Antitermination is an important mechanism of genetic regulation in bacteria, as well as eukaryotes - for example in the growth of HIV. Furthermore, expression of many cellular genes may be controlled by related processes that act at the level of transcript elongation. The extensive conservation of the large subunits of all RNA polymerases, which are mostly responsible for enzyme movement and RNA chain growth, suggests that there will be important common features in mechanisms of elongation control in many organisms. Interaction of E. coli RNA polymerase with the single 23 kD Q polypeptide, along with the accessory protein NusA, changes the elongation properties of the enzyme so that it goes through transcription terminators, and is less susceptible to some signals that induce pausing. Q modifies RNA polymerase at a well defined site that includes the late gene promoter, a Q binding site in DNA, and a DNA signal that induces transcriptional pausing; this signal acts primarily through interactions with the hon-transcribed strand. The action of Q on enzyme paused at this site may simulate Q function at terminators, because it promotes elongation through the pause. We will characterize this interaction and determine its relation to the activity of Q protein at terminators, and characterize the process of termination itself. We will dissect the Q protein to identify portions involved in DNA binding and in its interaction with RNA polymerase, using both genetic and biochemical methods. We will determine how the modification induced by Q persists from the promoter-associated engagement site throughout the process of transcription elongation.

我们的目标是了解大肠杆菌的 RNA 聚合酶是如何被修饰的 由噬菌体 lambda 基因 Q 编码的转录抗终止子。 抗终止是基因调控的重要机制 细菌以及真核生物 - 例如艾滋病毒的生长。 此外，许多细胞基因的表达可能受以下因素控制： 在转录本延伸水平上起作用的相关过程。这 所有 RNA 聚合酶的大亚基的广泛保护， 主要负责酶的运动和RNA链的生长， 表明在机制上将存在重要的共同特征 许多生物体中的伸长控制。大肠杆菌 RNA 的相互作用 聚合酶与单个 23 kD Q 多肽以及附件 蛋白质 NusA，改变酶的延伸特性，使其 通过转录终止子，并且不太容易受到某些 引起暂停的信号。 Q 以明确定义的方式修饰 RNA 聚合酶 位点，包括晚期基因启动子、DNA 中的 Q 结合位点，以及 诱导转录暂停的 DNA 信号；该信号起作用 主要通过与转录链的相互作用。这 Q 对在此位点暂停的酶的作用可以模拟 Q 的功能 终止子，因为它通过暂停促进伸长。我们将 描述这种相互作用并确定其与活动的关系 Q 蛋白在终止子处的表达，并表征终止过程 本身。我们将解剖 Q 蛋白以识别参与的部分 DNA 结合及其与 RNA 聚合酶的相互作用，同时使用 遗传和生化方法。我们将确定如何修改 由 Q 诱导的启动子相关接合位点持续存在 整个转录延伸过程。