2GWC

Crystal structure of plant glutamate cysteine ligase in complex with a transition state analogue

2GWC の概要

• エントリーDOI: 10.2210/pdb2gwc/pdb
• 分子名称: Glutamate cysteine ligase, MAGNESIUM ION, (2S)-2-amino-4-(S-butylsulfonimidoyl)butanoic acid, ... (4 entities in total)
• 機能のキーワード: disulfide bridges, glutathione biosynthesis, beta-hairpin, redox regulation, ligase
• 由来する生物種: Brassica juncea
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 416519.13

構造登録者

Hothorn, M.,Wachter, A.,Gromes, R.,Stuwe, T.,Rausch, T.,Scheffzek, K. (登録日: 2006-05-04, 公開日: 2006-06-20, 最終更新日: 2024-10-30)

主引用文献

Hothorn, M.,Wachter, A.,Gromes, R.,Stuwe, T.,Rausch, T.,Scheffzek, K.
Structural basis for the redox control of plant glutamate cysteine ligase.
J.Biol.Chem., 281:27557-27565, 2006

PubMed Abstract: Glutathione (GSH) plays a crucial role in plant metabolism and stress response. The rate-limiting step in the biosynthesis of GSH is catalyzed by glutamate cysteine ligase (GCL) the activity of which is tightly regulated. The regulation of plant GCLs is poorly understood. The crystal structure of substrate-bound GCL from Brassica juncea at 2.1-A resolution reveals a plant-unique regulatory mechanism based on two intramolecular redox-sensitive disulfide bonds. Reduction of one disulfide bond allows a beta-hairpin motif to shield the active site of B. juncea GCL, thereby preventing the access of substrates. Reduction of the second disulfide bond reversibly controls dimer to monomer transition of B. juncea GCL that is associated with a significant inactivation of the enzyme. These regulatory events provide a molecular link between high GSH levels in the plant cell and associated down-regulation of its biosynthesis. Furthermore, known mutations in the Arabidopsis GCL gene affect residues in the close proximity of the active site and thus explain the decreased GSH levels in mutant plants. In particular, the mutation in rax1-1 plants causes impaired binding of cysteine.

PubMed: 16766527
DOI: 10.1074/jbc.M602770200

実験手法

X-RAY DIFFRACTION (2.18 Å)