MUTATIONS AFFECTING THE PRODUCTION OF MATURE RNAS

这项拟议的研究的目标是了解 真核细胞前-tRNA和前-rRNA成熟和 在这些过程中起作用的基因产物。总而言之， 生物体的初始转录可能与 在蛋白质合成中起作用的成熟RNA。尽管在那里 是否概述了生成成熟产品所需步骤 TRNAs和rRNAs，几种催化核溶解的酶， 对剪接和修饰反应进行了表征和 编码和调节这些活动的基因甚至更少 已经被研究过了。此外，已知Pre-rRNA 处理步骤发生在核核颗粒上，并且有可能 这样的颗粒参与了前tRNA的加工。因此， 负责催化的基因产品以外的其他基因产品 处理反应也可能需要活动。 我们正在利用遗传、分子和生化方法来 回答关于Pre-tRNA加工的四个问题 酿酒酵母中的Pre-rRNA：(1)Pre-rRNA的哪些部分 核糖核酸对加工机械很重要吗？我们会研究 单个核糖体对前tRNA加工的体内影响 编码tRNatyr的基因突变；(2)什么产物 参与了前tRNA的加工？我们正试图确定， 通过突变或基因放大，影响 TRNA的成熟；(3)前tRNA加工与 辅助超结构蛋白？(4)有什么功能？ 以前被证明影响前tRNA和 核糖核酸前处理？我们现在已经确定了6个基因(RNA1， 影响加工的SRN1、LOS1、PC6、RRP1和SRD1)。 令人惊讶的是，这些代码似乎都不是已知的 催化活性，因此这些基因可能有助于 确定生化产品中意想不到的产品 加工反应的途径。我们的学习方法 这些基因是为了克隆野生型基因，进行基因定位 酵母中的产物，以生物化学的方式表征这些 产品，并确定其他具有相关功能的基因。

The goal of the proposed research is to gain an understanding of the steps of eukaryotic pre-tRNA and pre-rRNA maturation and the gene products that play a role in these processes. In all organisms initial transcripts can differ significantly from the mature RNAs that function in protein synthesis. Although there is a general outling of the steps necessary to generate mature tRNAs and rRNAs, few of the enzymes that catalyze nucleolytic, splicing and modification reactions have been characterized and even fewer of the genes coding and regulating these activities have been studied. Furthermore, it is known that pre-rRNA processing steps occur upon ribonuclear particles and it is possible that such particles participate in pre-tRNA processing. Thus, gene products other than those responsible for the catalytic activities are also likely to be required for processing reactions. We are utilizing genetic, molecular and biochemical approaches to answer four questions regarding the processing of pre-tRNA and pre-rRNAs in Saccharomyces cerevisiae: (1) What parts of pre- tRNAs are important to the processing machinery? We will study the in vivo consequences upon pre-tRNA processing of single mutations in a gene encoding tRNATyr; (2) What products are involved in pre-tRNA processing? We are attempting to identify, by mutation or by gene amplification, genes that affect the maturation of tRNA; (3) Is pre-tRNA processing associated with ancillary superstructural proteins? (4) What are the functions of the genes that previously had been shown to affect pre-tRNA and pre-rRNA processing? We have now identified 6 genes (RNA1, SRN1, LOS1, pC6, RRP1 and SRD1) that affect processing. Surprisingly, it does not appear that any of these code for known catalytic activities and therefore these genes may serve to identify products that were unanticipated from the biochemical pathways of the processing reactions. Our approach to study these genes is to clone the wild-type genes, to locate the gene products within yeast, to biochemically characterize these products, and to identify other genes with related functions.