ACTIVATION AND CONTROL OF RRNA TRANSCRIPTION

在大肠杆菌中，核糖体的合成主要控制在 RRNA转录起始阶段。RRNA可以解释AS 高达50%的瞬时细胞RNA合成。为了 了解蛋白质合成装置的生物合成， 影响上游激活和生长速度的因素 对rRNA合成的依赖调节正在进行研究。 RRNA启动子-RNA聚合酶联合的机制是 正在使用动力学和足迹方法进行研究。这将是 导致确定所涉及的各个步骤 RrnB PL启动子的转录启动及其影响因素 对每一步都有影响。所需的特定DNA序列 对于上游激活和增长速度控制将定义为 位点突变的构建和筛选，随后进行 操纵子在体内融合。最后，职位的重要性， 上游激活子序列的定位和构象 (UAS)相对于启动者，以及使用 UAS将增强来自异源启动子的转录 也可以在体内使用操纵子融合进行检查。

In E. coli, the synthesis of ribosomes is controlled primarily at the stage of rRNA transcription initiation. rRNA can account for as much as 50% of instantaneous cellular RNA synthesis. In order to understand the biosynthesis of the protein synthetic apparatus, factors involved in the upstream activation and growth rate dependent regulation of rRNA synthesis are being investigated. The mechanism of rRNA promoter-RNA polymerase association is being studied using kinetic and footprinting methods. This will lead to the identification of the individual steps involved in transcription initiation at the rrnB PL promoter and the factors that influence each step. The specific DNA sequences required for upstream activation and growth rate control will be defined by construction and selection of site mutations, followed by assay of operon fusions in vivo. Finally, the importance of position, orientation, and conformation of the upstream activator sequence (UAS) relative to the promoter and the feasibility of using the UAS to enhance transcription from heterologous promoters will also be examined using operon fusions in vivo.