FUNCTIONAL ROLE OF RIBOSOMAL RNA IN TRANSLATION

这项研究的总体目标是确定细胞的功能作用 核糖体RNA(RRNA)在翻译机制中的作用。具体项目 被设计来分析rRNA分子的细节 大肠埃希菌。这些项目将涉及两个相关领域：1) 系统发育保守的核苷酸在人类进化过程中的作用 翻译。单个rRNA核苷酸的功能意义将 点突变分析及突变体的鉴定 功能。具体地说，16S rRNA 790区域的突变将是 构建以探索rRNA在蛋白质起始中的作用 综合。此外，涉及相同790的补偿性突变 区域和23S rRNA的2755区域将测试双分子相互作用 核糖体亚单位联合模型。2660区的变化 也将对23S rRNA进行分析，以了解伸长因素 与rRNA相互作用；2)三级结构和功能 RRNA内的相互作用部位。几个更高阶的相互作用 是根据rRNA序列的系统发育比较提出的。这些 站点将通过补偿性站点定向进行试验性测试 诱变。诱变方法将首先应用于提出的 16S rRNA中央结构域中的假结和孤对相互作用。 随后，一个非正则孤子对被提议在 23S rRNA的肽基转移酶中心将发生突变。一起， 这些项目的结果将有助于确定 翻译中的rRNA。这反过来又将显著增加我们的 将RNA理解为细胞中的动态功能分子。

The overall goal of this research is to determine the functional role of ribosomal RNA (rRNA) in the mechanism of translation. Specific projects have been designed to analyze the details of rRNA molecules from Escherichia coli. These projects will address two related areas: 1) The role of phylogenetically conserved nucleotides in the process of translation. The functional significance of single rRNA nucleotides will be analyzed by site-directed mutagenesis and characterization of mutant function. Specifically, mutations in the 790 region of 16S rRNA will be constructed to explore the role of rRNA in the initiation of protein synthesis. In addition, compensatory mutations involving the same 790 region and the 2755 region of 23S rRNA will test a bimolecular interaction model for ribosomal subunit association. Alterations in the 2660 region of 23S rRNA will also be analyzed to understand how elongation factors interact with rRNA; and 2) The structure and function of tertiary interaction sites within rRNA. Several higher order interactions have been proposed based on phylogenetic comparisons of rRNA sequences. These sites will be tested experimentally by compensatory site-directed mutagenesis. The mutagenic approach will be applied first to proposed pseudoknot and lone pair interactions in the central domain of 16S rRNA. Subsequently, a non-canonical lone pair which is proposed to form in the peptidyl transferase center of 23S rRNA will be mutagenized. Together, the results from these projects will help to define the functional role of rRNA in translation. This in turn will add significantly to our understanding of RNA as a dynamic functional molecule in the cell.