MAMMALIAN AMINOACYL-TRNA SYNTHETASE COMPLEXES

氨基酰基-tRNA合成酶是一类酶家族，它发挥着重要的作用 在蛋白质生物合成的初始步骤中发挥不可或缺的作用 催化氨基酸同源tRNA合成氨基酰基tRNA 和ATP通过高度选择性的分子间相互作用。几种酶 在细菌中以游离酶的形式存在，但作为 哺乳动物细胞中的多酶复合体。初步结构 氨基酰基-tRNA合成酶复合体的表征 被执行。合成酶的联合的功能根本不是 明白了。拟议的研究计划分析结构和 合成酶复合体的功能。在结构分析中， 合成酶复合体中单个合成酶的亚基结构将 由纯化的合成酶的物理特性确定， 亲和标记和免疫化学方法，以及空间排列 合成酶复合体中不同蛋白质的组合将通过 免疫抑制、化学交联和电子显微镜。在 功能分析，我们计划调查可能存在的 合成酶复合体中的调节因子或通道机制， 合成酶复合体与其他化合物的结构和功能相互作用 蛋白质生物合成中的成分，并调查任何 在合成酶复合体中具有已知功能的蛋白质。这些研究 可以在更高层次的结构中提供基本原则 蛋白质的组织和功能的定量评估 这样的蛋白质结构在进化过程中。

Aminoacyl-tRNA synthetases are a family of enzymes which play an indispensable role in the initial steps of protein biosynthesis by catalyzing the formation of aminoacyl-tRNA from amino acid, cognate tRNA and ATP by highly selective intermolecular interactions. Several enzymes of this family occur as free soluble enzymes in bateria, but as multi-enzyme complexes in mammalian cells. Preliminary structural characterization of the aminoacyl-tRNA synthetase complexes has been carried out. The function of the association of synthetases is not at all understood. The proposed research plans to analyze the structure and the function of the synthetase complexes. In the structural analysis, the subunit structures of individual synthetases in the synthetase complex will be determined by physical characterization of purified synthetases, affinity labeling and immunochemical methods, and the spatial arrangement of different proteins in the synthetase complex will be examined by immuno-inhibition, chemical cross-linking and electron microscopy. In the functional analysis, we plan to investigate the possible presence of regulatory factors or channeling mechanisms in the synthetase complex, the structural and functional interaction of synthetase complexes with other components in protein biosynthesis, and to survey the presence of any proteins with known functions in the synthetase complexes. These studies may provide fundamental principles in the higher order of structural organization of proteins and a quantitative assessment of the function of such protein structure during evolution.