5CAE

Succinate bound to pig GTP-specific succinyl-CoA synthetase

5CAE の概要

• エントリーDOI: 10.2210/pdb5cae/pdb
• 関連するPDBエントリー: 1EUC 1EUD 2FP4 2FPG 2FPI 2FPP 4XX0
• 分子名称: Succinyl-CoA ligase [ADP/GDP-forming] subunit alpha, mitochondrial, Succinyl-CoA ligase [GDP-forming] subunit beta, mitochondrial, COENZYME A, ... (9 entities in total)
• 機能のキーワード: ligase
• 由来する生物種: Sus scrofa (Pig); 詳細
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 77023.36

構造登録者

Huang, J.,Fraser, M.E. (登録日: 2015-06-29, 公開日: 2016-06-29, 最終更新日: 2024-10-23)

主引用文献

Huang, J.,Fraser, M.E.
Structural basis for the binding of succinate to succinyl-CoA synthetase.
Acta Crystallogr D Struct Biol, 72:912-921, 2016

PubMed Abstract: Succinyl-CoA synthetase catalyzes the only step in the citric acid cycle that provides substrate-level phosphorylation. Although the binding sites for the substrates CoA, phosphate, and the nucleotides ADP and ATP or GDP and GTP have been identified, the binding site for succinate has not. To determine this binding site, pig GTP-specific succinyl-CoA synthetase was crystallized in the presence of succinate, magnesium ions and CoA, and the structure of the complex was determined by X-ray crystallography to 2.2 Å resolution. Succinate binds in the carboxy-terminal domain of the β-subunit. The succinate-binding site is near both the active-site histidine residue that is phosphorylated in the reaction and the free thiol of CoA. The carboxy-terminal domain rearranges when succinate binds, burying this active site. However, succinate is not in position for transfer of the phosphoryl group from phosphohistidine. Here, it is proposed that when the active-site histidine residue has been phosphorylated by GTP, the phosphohistidine displaces phosphate and triggers the movement of the carboxylate of succinate into position to be phosphorylated. The structure shows why succinyl-CoA synthetase is specific for succinate and does not react appreciably with citrate nor with the other C4-dicarboxylic acids of the citric acid cycle, fumarate and oxaloacetate, but shows some activity with L-malate.

PubMed: 27487822
DOI: 10.1107/S2059798316010044

実験手法

X-RAY DIFFRACTION (2.2 Å)