SERYL-TRNA SYNTHETASES: EVOLUTION AND DIVERSITY

Seryl-TRNA 合成酶：进化和多样性

• 批准号: 6629366
• 负责人: DIETER SOLL
• 金额: $ 3.9万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-02-09 至 2005-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6629366
• 关键词: Archaea; X ray crystallography; aminoacid tRNA ligase; binding sites; biochemical evolution; enzyme biosynthesis; enzyme substrate; genetic manipulation; intermolecular interaction; mass spectrometry; protein structure function; serine; transfer RNA

We will investigate the co-adaptations of seryl-tRNA synthetase (SerRS), a well studied class II aminoacyl-tRNA synthetase, with tRNAs through evolution. The availability of many genomic sequences enables us to clone the genes encoding SerRS enzymes from the different taxonomic domains. During the previous NIH-FIRCA grant (supporting the collaboration with Dr. Ivana Weygand-Durasevic), we focused on identifying the differences in tRNA:aminoacyl-tRNA synthetase specificities characteristic for the distinct protein synthesizing compartments of eukaryotic cells (mitochondria and chloroplasts). Until recently, the study of aminoacyl-tRNA synthesis in archaea had received little attention. The sequencing of the first archaeal genome (Methanococcus jannaschii) revealed the "lack" of few canonical aminoacyl-tRNA synthetases, including the one specific for serine. However, biochemical analysis of purified and heterologously expressed SerRS-encoding (serS) genes from two other methanogens, Methanoacterium thermoautotrophicum and Methanococcus maripaludis, showed that these proteins are SerRS enzymes. Thus, there are three types of SerRS found in the archaea. The enzyme from the halophilic archaeon Haloarcula marismortui has high sequence similarity to bacterial SerRS proteins, while phylogenetic analyses revealed in other archaea a different clade with sequence similarity to the eukaryotic enzymes. In contrast, the three methanogenic archaea contain genes that display only low sequence similarity to the known serS genes from all other organisms and encode a structurally uncommon enzyme. In the proposed project we will pursue detailed biochemical, mutational, and structural studies with the aim of elucidating the structure-function relationships in these unusual seryl-tRNA synthetases. These studies will complement our ongoing projects on the identification and characterization of components involved in aminoacyl-tRNA synthesis in the living kingdom.

我们将研究Seryl-tRNA合成酶（SERRS）的共同适应 研究了II类氨基酰基-TRNA合成酶，并通过进化通过TRNA。这 许多基因组序列的可用性使我们能够克隆编码的基因 来自不同分类领域的SERRS酶。在上一个 NIH-FIRCA Grant（支持与Ivana博士的合作 Weygand-durasevic），我们专注于确定 tRNA：氨基酰基-TRNA合成酶特异性特征的特征 真核细胞的蛋白质合成室（线粒体和线粒体 叶绿体）。直到最近，对古细菌的氨基酰基-TRNA合成的研究 很少受到关注。第一个古细胞基因组的测序 （Jannaschii的甲虫）揭示了几乎没有规范氨基酰基-TRNA的“缺乏” 合成酶，包括一种特定于丝氨酸的酶。但是，生化 分析纯化和异源表达的SERR编码（SERS）基因 来自另外两种甲烷剂，甲烷杆菌的热养生和 甲虫球菌表明这些蛋白质是锯齿酶。因此， 古细菌中发现了三种类型的锯齿。来自 卤素古老的Haloarcula marismortui与 细菌锯齿蛋白，而在其他古细菌中揭示的系统发育分析 与真核酶相似的不同进化枝。在 对比，三个甲烷作古细菌包含仅显示低的基因 与来自所有其他生物的已知SER基因的序列相似性和编码 结构上罕见的酶。在拟议的项目中，我们将详细介绍 生化，突变和结构研究，目的是阐明 这些不寻常的塞基-TRNA合成酶中的结构功能关系。这些 研究将补充我们正在进行的识别和 参与氨基酰基-TRNA合成的成分的表征 活王国。