2VPS

Structure Of The Bifunctional Leishmania Major Trypanothione Synthetase-Amidase

2VPS の概要

• エントリーDOI: 10.2210/pdb2vps/pdb
• 関連するPDBエントリー: 2VOB 2VPM
• 分子名称: TRYPANOTHIONE SYNTHETASE, CHLORIDE ION, BROMIDE ION, ... (4 entities in total)
• 機能のキーワード: ligase
• 由来する生物種: LEISHMANIA MAJOR
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 74867.09

構造登録者

Fyfe, P.K.,Oza, S.L.,Fairlamb, A.H.,Hunter, W.N. (登録日: 2008-03-04, 公開日: 2008-05-06, 最終更新日: 2023-12-13)

主引用文献

Fyfe, P.K.,Oza, S.L.,Fairlamb, A.H.,Hunter, W.N.
Leishmania Trypanothione Synthetase-Amidase Structure Reveals a Basis for Regulation of Conflicting Synthetic and Hydrolytic Activities.
J.Biol.Chem., 283:17672-, 2008

PubMed Abstract: The bifunctional trypanothione synthetase-amidase catalyzes biosynthesis and hydrolysis of the glutathione-spermidine adduct trypanothione, the principal intracellular thiol-redox metabolite in parasitic trypanosomatids. These parasites are unique with regard to their reliance on trypanothione to determine intracellular thiol-redox balance in defense against oxidative and chemical stress and to regulate polyamine levels. Enzymes involved in trypanothione biosynthesis provide essential biological activities, and those absent from humans or for which orthologues are sufficiently distinct are attractive targets to underpin anti-parasitic drug discovery. The structure of Leishmania major trypanothione synthetase-amidase, determined in three crystal forms, reveals two catalytic domains. The N-terminal domain, a cysteine, histidine-dependent amidohydrolase/peptidase amidase, is a papain-like cysteine protease, and the C-terminal synthetase domain displays an ATP-grasp family fold common to C:N ligases. Modeling of substrates into each active site provides insight into the specificity and reactivity of this unusual enzyme, which is able to catalyze four reactions. The domain orientation is distinct from that observed in a related bacterial glutathionylspermidine synthetase. In trypanothione synthetase-amidase, the interactions formed by the C terminus, binding in and restricting access to the amidase active site, suggest that the balance of ligation and hydrolytic activity is directly influenced by the alignment of the domains with respect to each other and implicate conformational changes with amidase activity. The potential inhibitory role of the C terminus provides a mechanism to control relative levels of the critical metabolites, trypanothione, glutathionylspermidine, and spermidine in Leishmania.

PubMed: 18420578
DOI: 10.1074/JBC.M801850200

実験手法

X-RAY DIFFRACTION (2.75 Å)