MAMMALIAN AMINOACYL-TRNA SYNTHETASE COMPLEX

拟议研究的目的是阐明 结构-功能关系与哺乳动物的调控 氨酰-tRNA合成酶。 除了氨酰化同源转运RNA 对于蛋白质生物合成，哺乳动物合成酶参与 细胞内蛋白水解、信号核苷酸（AppppA）合成 和类似物）氨基酸转运、自身免疫性疾病和衰老。 至少有八种哺乳动物氨酰-tRNA合成酶 结合成多酶复合物。 合成酶复合体 呈现出一种独特而有趣的生物化学排列， 结构和监管。 该研究项目提出， 在最高层次上描述基本原则， 蛋白质的结构组织，以及 这种蛋白质结构。 拟议项目的具体目标 1）哺乳动物氨酰-tRNA的克隆和测序 合成酶，并获得这些酶的高水平表达 哺乳动物细胞中的合成酶; 2）确定氨基酸 参与合成酶复合物组装的序列，和 为了在体内研究合成酶复合物在 合成酶周转和信号核苷酸生物合成; 3） 研究氨酰-tRNA合成酶与 合成酶复合物，并分析其在合成中的作用 信号核苷酸和哺乳动物蛋白质生物合成; 4） 克隆和定位氨酰-tRNA合成酶的基因， 确定剪接位点和调控序列， 上游侧翼区。 将使用的方法是 酶学、结构和遗传学。 鉴于中心作用 蛋白质在所有细胞功能中的作用，对结构的理解， 蛋白质中这些必需酶的功能和调节 生物合成非常重要。

The objective of the proposed research is to elucidate the structure-function relationship and the regulation of mammalian aminoacyl-tRNA synthetases. Besides aminoacylating cognate tRNAs for protein biosynthesis, mammalian synthetases participate in intracellular proteolysis, synthesis of signal nucleotides (AppppA and analogs) amino acid transport, autoimmune diseases and aging. At least eight of the mammalian aminoacyl-tRNA synthetases associate as a multi-enzyme complex. The synthetase complex presents a unique and interesting biochemical arrangement in terms of both structure and regulation. This research project proposes to delineate the fundamental principles in the high order of structural organization of proteins, and the evolved functions of such protein structure. The specific aims of the proposed projects are: 1) to clone and sequence mammalian aminoacyl-tRNA synthetases, and to obtain high level of expression of these synthetases in mammalian cells; 2) to determine the amino acid sequences involved in the assembly of the synthetase complex, and to study in vivo the roles of the synthetase complex in the synthetase turnover and the signal nucleotide biosynthesis; 3) to study in vitro the interaction of aminoacyl-tRNA synthetases with the synthetase complex, and to analyze its roles in the synthesis of signal nucleotide and mammalian protein biosynthesis; 4) to clone and map the genes of aminoacyl-tRNA synthetases, and determine the splicing sites and the regulatory sequences in the upstream flanking region. The methods to be used will be enzymological, structural and genetic. In view of the central role of proteins in all cell functions, understanding of the structure, function and the regulation of these essential enzymes in protein biosynthesis is of great importance.