热球菌来源的谷氨酰-tRNA 合成酶（TtGlnRS）及其复合物的结构与功能分析。

Structural and functional analysis of Glutaminyl-tRNA synthetase (TtGlnRS) from Thermus thermophilus HB8 and its complexes.

机构信息

Structural Biology and Bio-Computing Lab, Department of Bioinformatics, Science Block, Alagappa University, Karaikudi 630 003, India.

Molecular Medicine - Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110 067, India.

出版信息

Int J Biol Macromol. 2018 Dec;120(Pt B):1379-1386. doi: 10.1016/j.ijbiomac.2018.09.115. Epub 2018 Sep 21.

DOI:10.1016/j.ijbiomac.2018.09.115

PMID:30248426

Abstract

Aminoacyl-tRNA synthetases (AaRSs) are vital enzymes for translation of proteins in cells. AaRSs catalyse the esterification of a specific amino acid to corresponding tRNAs to form an aminoacyl-tRNA that is used in ribosome-based protein synthesis. We focused on Glutaminyl tRNA synthetase (GlnRS) enzyme from the extreme thermophile Thermus thermophilus for structural studies. Our thermal shift assays show binding of enzyme substrates L-Gln and ATP as well as of various metals including cesium. We resolved crystal structures of apo-GlnRS as well as those in complex with AMP and ATP at 2.8 Å, 2.4 Å and 2.6 Å respectively. The bound cesium was found at the site of magnesium that typically binds to GlnRS. High structural conservation was evident in the Thermus thermophilus GlnRS when compared to those from Escherichia coli GlnRS.

摘要

氨酰-tRNA 合成酶（AaRSs）是细胞中蛋白质翻译的关键酶。AaRSs 催化特定氨基酸与相应 tRNA 的酯化反应，形成用于核糖体蛋白合成的氨酰-tRNA。我们专注于来自极端嗜热菌 Thermus thermophilus 的谷氨酰-tRNA 合成酶（GlnRS）进行结构研究。我们的热转移分析表明，酶底物 L-谷氨酰胺和 ATP 以及各种金属（包括铯）的结合。我们分别解析了 apo-GlnRS 以及与 AMP 和 ATP 形成复合物的晶体结构，分辨率分别为 2.8Å、2.4Å 和 2.6Å。结合的铯位于典型与 GlnRS 结合的镁位点。与来自大肠杆菌 GlnRS 的 GlnRS 相比，Thermus thermophilus GlnRS 的结构高度保守。