EUKARYOTIC TRNA MATURATION

真核 TRNA 成熟

• 批准号: 2444598
• 负责人: DAVID R ENGELKE
• 金额: $ 32.34万
• 依托单位: UNIVERSITY OF MICHIGAN AT ANN ARBOR
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-04-01 至 1999-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2444598
• 关键词: chemical binding; chemical cleavage; computer simulation; confocal scanning microscopy; crosslink; cytology; enzyme mechanism; enzyme model; enzyme structure; enzyme substrate; enzyme substrate complex; fungal genetics; genetic library; high performance liquid chromatography; immunoprecipitation; laboratory rabbit; molecular cloning; mutant; nucleic acid sequence; nucleic acid structure; pancreatic ribonuclease; protein purification; site directed mutagenesis; transfer RNA

Mature 5; termini of transfer RNAs (tRNAs) in both prokaryotes and eukaryotes are generated from precursor molecules by cleavage with a structure-specific endonuclease, RNase P. The enzyme contains both RNA and protein components, and the RNA component alone from either E. coli or B. subtilis can catalyze the correct cleavage. Further, the RNA and protein components from these two prokaryotes can e interchange to reconstitute RNase P holoenzymes even though the primary sequences of the two RNAs show little homology. Cleavage appears to precede through a mechanism distinct from those observed in RNA splicing reactions, as judged by cofactor requirements and the dependence on substrate structure, rather than sequence. Two forms of RNase P have been identified in the yeast S. cerevisiae; a nuclear form and a mitochondrial form from which only an RNA component is encoded in the mitochondrial DNA. We have isolated the nuclear form and sequenced the RNA component. This proposal details plans to: 1) characterize the RNase P RNA gene, 3) determine the solution structure of the RNase P holoenzyme and enzyme-substrate complex, 3) examine which features of the enzymic and substrate RNA structures are required for correct cleavage, 4) investigate the structure of the active site and mechanism of catalysis and 5) determine whether the mitochondrial and nuclear enzymic RNAs share the same protein component(s).

成熟5;培罗索和转移RNA（TRNA）的末端 真核生物是由前体分子通过裂解产生的 特定于结构的内切酶，RNaseP。酶含有 RNA和蛋白质成分，以及单独的RNA成分 大肠杆菌或枯草芽孢杆菌可以催化正确的裂解。 此外，来自这两个原核生物的RNA和蛋白质成分 可以互换以重新构建RNase P Holoenzymes 两个RNA的主要序列显示几乎没有同源性。 乳沟似乎是通过与那些不同的机制 在RNA剪接反应中观察到，如辅助因子所判断 要求和对底物结构的依赖，而不是 顺序。 在酵母中已经确定了两种形式的RNase P。 酿酒酵母；核形式和线粒体形式，只有从中 RNA成分编码在线粒体DNA中。 我们有 分离了核形式并测序了RNA成分。 这 提案详细信息计划：1）表征RNase P RNA基因， 3）确定RNase P Holoenzyme和 酶 - 基底络合物，3）检查酶的哪些特征 正确切割需要底物RNA结构，4） 研究主动位点的结构和机制 催化和5）确定线粒体和核是否是否 酶RNA共享相同的蛋白质成分。