STRUCTURE AND MECHANISM OF RIBOSOMAL RNA IN THE RIBOSOME

将通过以下方法研究大肠杆菌核糖体中的核糖体RNA： 物理技术来确定其三维结构， 确定其功能期间结构变化的性质和程度。 这些实验将基于16S的三维模型 rRNA在30S亚基，这是在目前的资助期。 将使用几种策略来获得结构信息， 监督内部结构;重点将放在使用 光化学试剂可以放置在特定的rRNA位点， 这些提供了关于选定区域的大量信息。的 最初的实验将集中在16S rRNA的结构， 序列位置560、700、790、900和1500，因为这些位置非常 靠近mRNA解码区。这个区域对于 的亚基和获得的结果将区分 替代rRNA折叠。当这个区域被解决时， 将对各地区进行调查。 具体的工作目标是：1.来确定 mRNA轨道下的16S rRNA结构，包括三个 区域：在tRNA解码位点，在解码区域的出口侧 (part 16S rRNA结构域II）和解码的入口侧 区域（16S rRNA的530茎环区域），2.以确定影响 抗生素结合和16S rRNA高阶上的16S rRNA突变 结构，3.为了确定16S rRNA的构象变化， 在tRNA结合过程中，在起始复合物中 起始因子IF3和在易位过程中，4.以确定是否 mRNA作为其30S亚基路径的一部分折叠， tRNA结合和易位对这种可能的折叠的影响。 核糖体是一个重要的研究课题，因为它执行 这是一个普遍的生化过程，我们还不知道它的分子机制， 续费增加对核糖体的了解将有助于我们理解 RNA的催化能力，以及我们对RNA的一般知识， 结构和核糖核蛋白结构。的一个重要方面 许多抗生素都是通过对抗生素的作用来发挥其活性的。 核糖体有必要了解这些相互作用的性质 以及它们对核糖体的影响， 合成抗生素

The ribosomal RNA in the Escherichia coli ribosome will be investigated by physical techniques to determine its three dimensional structure and to determine the nature and extent of structural change during its function. These experiments will be based on the three dimensional model of the 16S rRNA in the 30S subunit that was derived in the current grant period. Several strategies will be used to obtain structural information and monitor the internal structure; an emphasis will be on the use of photochemical reagents that can be placed at specific rRNA sites because these provide significant amounts of information about selected areas. The initial experiments will focus on the structure of the 16S rRNA around sequence positions 560, 700, 790, 900, and 1500 as these are located very close to the mRNA decoding region. This region is critical to the function of the subunit and the results obtained will distinguish between alternative rRNA foldings. When this region is solved, more peripheral regions will be investigated. The specific aims of the work are: 1. to determine the three dimensional structure of the 16S rRNA underlying the mRNA track, including three regions: at the tRNA decoding sites, at exit side of the decoding region (part of the 16S rRNA domain II) and on the entrance side of the decoding region (the 530 stem loop region of 16S rRNA), 2. to determine the effects of antibiotic binding and 16S rRNA mutations on the 16S rRNA higher order structure, 3. to determine conformational changes in the 16S rRNA higher order structure during tRNA binding, in the initiation complex with initiation factor IF3 and in the translocation process, 4. to determine if mRNA is folded as part of its path in the 30S subunit and the influence of tRNA binding and translocation on this possible folding. The ribosome is an important subject of investigation because it performs a universal biochemical process for which we do not yet know the molecular details. Increased knowledge of the ribosome will add to our understanding of the catalytic capacities of RNA, and to our general knowledge of RNA structure and ribonucleoprotein structure. An important aspect of the proposed studies is that many antibiotics exert their activity on the ribosome. It is necessary to understand the nature of these interactions and their affect on the ribosome if there is to be rational design of synthetic antibiotics.