链霉菌两类亮氨酸tRNA与相关蛋白质的相互作用

项目名称： 链霉菌两类亮氨酸tRNA与相关蛋白质的相互作用

项目编号： No.91440204

项目类型： 重大研究计划

立项/批准年度： 2015

项目学科： 生物科学

项目作者： 王恩多

作者单位： 中国科学院上海生命科学研究院

项目金额： 300万元

中文摘要： tRNA是非编码RNA。根据tRNA的可变茎环的短和长将tRNA分为I类和II类，原核细胞中和真核细胞质中只存在第II类亮氨酸tRNA（tRNALeu）；而真核细胞线粒体中还存在第I类tRNALeu。两种亮氨酰-tRNA合成酶(LeuRS)分别催化两类tRNALeu亮氨酰化。但在天蓝色链霉菌中兼有两类tRNALeu对应一种LeuRS。本申请将研究天蓝色链霉菌中两类tRNALeu与相关蛋白质的相互作用:研究这两种tRNALeu的高级结构的差异，如何被一种LeuRS识别，LeuRS识别两种tRNALeu的关键结构域，它们与修饰酶、延伸因子的相互识别，两种 tRNA与核糖体结合和翻译效率，发现未知的与两种tRNALeu相互作用的蛋白质，探索其新功能。构建第I类tRNALeu和LeuRS基因分别敲除的天蓝色链霉菌株，体内研究tRNALeu与LeuRS的相互作用及其功能，鉴定参与相互作用的关键残基。

中文关键词： 亮氨酸tRNA；链霉菌；相关蛋白质；亮氨酰-tRNA合成酶；相互作用

英文摘要： tRNA is a type of classic non-coding RNA. According to the length of variable arm, tRNAs can be divided into two classes. Most of the tRNAs belong to class I tRNA with a short variable arm, and a few tRNAs have long variable arm and belong to class II tRNA. Usually, the prokaryote and eukaryote cytoplasm only contain class II tRNALeus, however the eukaryote mitochondrion contains class I tRNALeus. Two types of LeuRS catalyze leucylation of the two classes of tRNALeus, respectively. Streptomyces is a rare species containing both class I and II of tRNALeus but only one LeuRS in its cytoplasm. In the project we will study the properties of the two types of tRNALeus and their interactions with the related proteins in Streptomyces coelicolor, including investigating the tertiary structure differences between the two kinds of tRNALeus, understanding how one LeuRS could recognize two tRNALeus, finding the crucial domain in LeuRS to recognize the two kinds of tRNALeus, comparing the different recognitions of the two types of tRNALeus to modification enzymes and elongation factors, and learning the translation efficiency of the two types of changed tRNALeus in ribosome. We will also search and identify the unknown proteins which could interact with these two types of tRNALeus to investigate the new functions of the tRNALeus. Additionally, we will obtain Streptomyces coelicolor strain with knockout genes encoding class I tRNALeu and the LeuRS separately to study the interaction and function of tRNALeu and LeuRS in vivo，and to identify the crucial residues which are important for interaction.

英文关键词： tRNALeu;Streptomyces ;relative protein;leucyl-tRNA synthetase;interaction