2NU9

C123aT Mutant of E. coli Succinyl-CoA Synthetase Orthorhombic Crystal Form

2NU9 の概要

• エントリーDOI: 10.2210/pdb2nu9/pdb
• 関連するPDBエントリー: 1JKJ 1JLL 2NU6 2NU7 2NU8 2NUA 2SCU
• 分子名称: Succinyl-CoA ligase [ADP-forming] subunit alpha, Succinyl-CoA synthetase beta chain, COENZYME A, ... (5 entities in total)
• 機能のキーワード: citric acid cycle, heterotetramer, ligase, atp-grasp fold, rossmann fold
• 由来する生物種: Escherichia coli; 詳細
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 288617.32

構造登録者

Fraser, M.E. (登録日: 2006-11-08, 公開日: 2007-07-24, 最終更新日: 2023-08-30)

主引用文献

Hidber, E.,Brownie, E.R.,Hayakawa, K.,Fraser, M.E.
Participation of Cys 123alpha of Escherichia coli Succinyl-CoA Synthetase in Catalysis
ACTA CRYSTALLOGR.,SECT.D, 63:876-884, 2007

PubMed Abstract: Succinyl-CoA synthetase has a highly conserved cysteine residue, Cys123alpha in the Escherichia coli enzyme, that is located near the CoA-binding site and the active-site histidine residue. To test whether the succinyl moiety of succinyl-CoA is transferred to the thiol of Cys123alpha as part of the catalytic mechanism, this residue was mutated to alanine, serine, threonine and valine. Each mutant protein was catalytically active, although less active than the wild type. This proved that the specific formation of a thioester bond with Cys123alpha is not part of the catalytic mechanism. To understand why the mutations affected catalysis, the crystal structures of the four mutant proteins were determined. The alanine mutant showed no structural changes yet had reduced activity, suggesting that the size of the cysteine is important for optimal activity. These results explain why this cysteine residue is conserved in the sequences of succinyl-CoA synthetases from different sources.

PubMed: 17642514
DOI: 10.1107/S0907444907029319

実験手法

X-RAY DIFFRACTION (2.9 Å)