POLYSOMES & SUBUNITS--STRUCTURE-FUNCTION RELATIONSHIPS

多聚体

• 批准号: 2173488
• 负责人: ALBERT E DAHLBERG
• 金额: $ 41.08万
• 依托单位: BROWN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 1975
• 资助国家: 美国
• 起止时间: 1975-09-01 至 1997-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2173488
• 关键词: Escherichia coli; chemical structure function; enzyme activity; enzyme mechanism; gene mutation; genetic enhancer element; genetic strain; genetic translation; intermolecular interaction; mutant; operon; plasmids; polysomes; protein biosynthesis; protein transport; ribosomal RNA; ribozymes; site directed mutagenesis; transcription termination; transfer RNA

The objective of this research proposal is to further the understanding of the catalytic role of rRNA in the process of translation. Our goal is to define regions in E. coli rRNA which are involved in particular functions during the different stages of protein synthesis. The primary approach of the laboratory involves mutagenesis of rRNA by in vitro and in vivo methods using a plasmid-borne rrnB operon. Plasmids, particular cell strains and mutagenic techniques have been developed to permit the isolation of lethal as well as nonlethal mutations in sufficient quantities for analysis. Structural and functional features of the mutants will be characterized by a variety of biochemical and genetic systems. Four major topics of translation will be investigated, in each of which rRNA has a central functional role. The four areas include I. Fidelity of translation; functional interactions between tRNA and rRNA. Mutants will be constructed by site-directed mutagenesis or selected for by systems such as TrpE91, following random mutagenesis, to study functional interactions between selected regions of tRNA and rRNA. II. Interactions between mRNA and rRNA at initiation and termination. Translational enhancers will be identified and characterized as will sites of functional interaction between mRNA and rRNA at termination. III. Peptidyl transferase activity in 23S rRNA. Mutations will be constructed at important functional sites involving tRNA and rRNA interactions in domain V of 23S rRNA. IV. The role of 4.5S rRNA, 16S, and 23S rRNA in transport of nascent proteins across the cell membrane. Mutations will be constructed at putative functional sites in 4.5S rRNA and the rRNAs, and effects on transport will be studied. It is anticipated that these studies will contribute to our understanding of the functional role of rRNA by defining in detail structural and functional features of particular regions of the rRNAs and their contributions to the overall process of protein synthesis.

这项研究提案的目的是加深对 RRNA在翻译过程中的催化作用。我们的目标 是定义E.ColirRNA中特定涉及的区域 在蛋白质合成的不同阶段发挥作用。这个 该实验室的主要方法包括通过in诱变rRNA。 体外和体内方法使用质粒携带的rrnB操纵子。质粒， 已经开发出了特定的细胞株和诱变技术 允许分离出致命和非致命的突变 分析所需的足够数量。结构和功能特点 突变体的特征将是各种生化和 遗传系统。翻译的四个主要主题是 研究发现，rRNA在每一个过程中都发挥着核心作用。这个 四个方面包括：一、翻译的保真度；功能互动 在tRNA和rRNA之间。突变体将通过定点定向构建 突变或由TrpE91等系统选择进行的，遵循随机 突变，研究选定区域之间的功能相互作用 TRNA和rRNA。II.启动时信使核糖核酸和核糖核酸的相互作用 和终结者。将确定翻译增强剂，并 其特征是mRNAs和mRNAs之间的功能相互作用的意志位点 终止时的rRNA。III.23S rRNA中肽转移酶的活性。 突变将在重要的功能位点上构建，包括 23S rRNA V区的tRNA和rRNA相互作用。四、政府部门的作用 4.5S rRNA、16S和23S rRNA在新生蛋白跨膜转运中的作用 细胞膜。突变将被构建在假定的 4.5S rRNA和rRNA中的功能位点及其对运输的影响 将会被研究。预计这些研究将有助于 来帮助我们理解rRNA的功能作用 详细的结构和功能特征的特定区域的 核糖核酸及其在蛋白质整个过程中的作用 综合。