MECHANISM, ACTIVATION AND CONTROL OF RRNA TRANSCRIPTION

RRNA转录的机制、激活和控制

• 批准号: 2178655
• 负责人: Richard L. Gourse
• 金额: $ 28.42万
• 依托单位: UNIVERSITY OF WISCONSIN-MADISON
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-07-01 至 1999-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2178655
• 关键词: MECHANISM; ACTIVATION; CONTROL; RRNA; TRANSCRIPTION

DESCRIPTION: The ribosome is the central component of protein synthesis in all cells. In E. coli, the rate of ribosomal RNA synthesis determines the rate of ribosome synthesis. Multiple mechanisms contribute to the expression of rRNA. A cis-acting sequence (the UP Element) and a trans-acting protein (FIS) account for the high activity of rRNA promoters. In addition, at least two regulatory factors, ppGpp and an unidentified feedback regulator, account for the stringent control and growth rate dependent control of rRNA transcription, respectively. In the next funding period, experiments are proposed to determine the mechanism by which the known activators and regulators affect RNA polymerase and to identify the remaining effectors that influence rRNA transcription. These studies have broad implications not only for our understanding of ribosome synthesis in bacteria, but also for our understanding of basic transcription mechanisms in prokaryotes and eukaryotes. The molecular details of the interactions between the components involved in transcription activation of rrn P1 promoters (RNAP, the UP Element, and FIS) will be determined. Recognition of the UP Element by RNAP represents a new paradigm in our picture of bacterial transcription. The study of FIS-RNAP interactions is also of interest, since FIS- dependent activation represents an activation class unlike those characterized previously. Thus, the identification of the critical residues in RNAP affecting UP Element and FIS utilization and the development of an UP Element consensus sequence should be major contributions to our understanding of transcription. Potential roles of both the alpha and sigma subunits of RNAP will be investigated. Both genetic and biochemical approaches to these problems are described. Compensating effects between multiple regulators have obscured the ability to determine the responses of individual systems to specific environmental signals affecting rRNA transcription. The cis-acting targets for all the known mechanisms affecting transcription from rrnB P1 have now been identified. By utilizing promoter mutations which selectively eliminate promoter responses to FIS, ppGpp, or feedback, it should be possible to determine the contribution of FIS-dependent activation to rRNA expression at specific times, the mechanism of transcription inhibition by ppGpp, and the molecular identity of the feedback regulator.

描述：核糖体是蛋白质合成的中心组成部分 在所有的细胞。 在大肠大肠杆菌核糖体RNA合成速率 决定核糖体合成的速率。 多种机制 有助于rRNA的表达。 顺式作用序列（UP 元件）和反式作用蛋白（FIS）解释了高活性 rRNA启动子 此外，至少有两个调节因素，ppGpp 和一个身份不明的反馈调节器，占严格的 rRNA转录的控制和生长速率依赖性控制， 分别 在下一个供资期内，建议进行试验， 确定已知激活剂和调节剂的作用机制 影响RNA聚合酶，并确定其余的效应子， 影响rRNA转录。 这些研究具有广泛的影响， 不仅有助于我们理解细菌中的核糖体合成， 对于我们理解原核生物的基本转录机制 和真核生物 所涉及的组分之间相互作用的分子细节 在rrnP 1启动子（RNAP，UP元件， 和FIS）将被确定。 RNAP对UP元素的识别 代表了我们对细菌转录的一种新的模式。 FIS-RNAP相互作用的研究也很有意义，因为FIS-RNAP相互作用的研究也很有意义。 依赖激活表示一个激活类， 以前的特点。 因此，关键的识别 RNAP中影响UP元件和FIS利用的残基以及 UP元件共有序列的开发应该是主要的 对我们理解转录的贡献。 潜在作用 将研究RNAP的α和σ亚基。 两 描述了解决这些问题的遗传和生物化学方法。 多个监管机构之间的补偿效应掩盖了 确定单个系统对特定 影响rRNA转录的环境信号。 顺式作用 所有已知影响rrnB转录机制的靶点 P1已经确定。 通过利用启动子突变， 选择性消除启动子对FIS、ppGpp或反馈的应答， 应可确定依赖于金融信息系统的 在特定时间激活rRNA表达， 通过ppGpp的转录抑制，以及 反馈调节器