1KMN

HISTIDYL-TRNA SYNTHETASE COMPLEXED WITH HISTIDINOL AND ATP

1KMN の概要

• エントリーDOI: 10.2210/pdb1kmn/pdb
• 分子名称: HISTIDYL-TRNA SYNTHETASE, L-histidinol, ADENOSINE-5'-TRIPHOSPHATE, ... (4 entities in total)
• 機能のキーワード: aminoacyl-trna synthase, ligase, synthetase
• 由来する生物種: Escherichia coli
• 細胞内の位置: Cytoplasm: P60906
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 190938.70

構造登録者

Arnez, J.G.,Francklyn, C.S.,Moras, D. (登録日: 1997-05-09, 公開日: 1997-12-17, 最終更新日: 2023-11-15)

主引用文献

Arnez, J.G.,Augustine, J.G.,Moras, D.,Francklyn, C.S.
The first step of aminoacylation at the atomic level in histidyl-tRNA synthetase.
Proc.Natl.Acad.Sci.USA, 94:7144-7149, 1997

PubMed Abstract: The crystal structure of an enzyme-substrate complex with histidyl-tRNA synthetase from Escherichia coli, ATP, and the amino acid analog histidinol is described and compared with the previously obtained enzyme-product complex with histidyl-adenylate. An active site arginine, Arg-259, unique to all histidyl-tRNA synthetases, plays the role of the catalytic magnesium ion seen in seryl-tRNA synthetase. When Arg-259 is substituted with histidine, the apparent second order rate constant (kcat/Km) for the pyrophosphate exchange reaction and the aminoacylation reaction decreases 1,000-fold and 500-fold, respectively. Crystals soaked with MnCl2 reveal the existence of two metal binding sites between beta- and gamma-phosphates; these sites appear to stabilize the conformation of the pyrophosphate. The use of both conserved metal ions and arginine in phosphoryl transfer provides evidence of significant early functional divergence of class II aminoacyl-tRNA synthetases.

PubMed: 9207058
DOI: 10.1073/pnas.94.14.7144

実験手法

X-RAY DIFFRACTION (2.8 Å)