3H99

Structure of a mutant methionyl-tRNA synthetase with modified specificity complexed with methionine

3H99 の概要

• エントリーDOI: 10.2210/pdb3h99/pdb
• 関連するPDBエントリー: 1QQT 3H97 3H9B 3H9C
• 分子名称: Methionyl-tRNA synthetase, METHIONINE, ZINC ION, ... (5 entities in total)
• 機能のキーワード: rossmann fold, aminoacyl-trna synthetase, atp-binding, ligase, metal-binding, nucleotide-binding, protein biosynthesis, rna-binding, trna-binding
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cytoplasm: P00959
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 64506.07

構造登録者

Schmitt, E.,Tanrikulu, I.C.,Yoo, T.H.,Panvert, M.,Tirrell, D.A.,Mechulam, Y. (登録日: 2009-04-30, 公開日: 2009-12-08, 最終更新日: 2023-09-06)

主引用文献

Schmitt, E.,Tanrikulu, I.C.,Yoo, T.H.,Panvert, M.,Tirrell, D.A.,Mechulam, Y.
Switching from an induced-fit to a lock-and-key mechanism in an aminoacyl-tRNA synthetase with modified specificity.
J.Mol.Biol., 394:843-851, 2009

PubMed Abstract: Methionyl-tRNA synthetase (MetRS) specifically binds its methionine substrate in an induced-fit mechanism, with methionine binding causing large rearrangements. Mutated MetRS able to efficiently aminoacylate the methionine (Met) analog azidonorleucine (Anl) have been identified by saturation mutagenesis combined with in vivo screening procedures. Here, the crystal structure of such a mutated MetRS was determined in the apo form as well as complexed with Met or Anl (1.4 to 1.7 A resolution) to reveal the structural basis for the altered specificity. The mutations result in both the loss of important contacts with Met and the creation of new contacts with Anl, thereby explaining the specificity shift. Surprisingly, the conformation induced by Met binding in wild-type MetRS already occurs in the apo form of the mutant enzyme. Therefore, the mutations cause the enzyme to switch from an induced-fit mechanism to a lock-and-key one, thereby enhancing its catalytic efficiency.

PubMed: 19837083
DOI: 10.1016/j.jmb.2009.10.016

実験手法

X-RAY DIFFRACTION (1.4 Å)