3A30

E. coli Gsp amidase C59 acetate modification

3A30 の概要

• エントリーDOI: 10.2210/pdb3a30/pdb
• 関連するPDBエントリー: 2iob 3a2y 3a2z
• 分子名称: Bifunctional glutathionylspermidine synthetase/amidase, ACETATE ION (3 entities in total)
• 機能のキーワード: gsp amidase, atp-binding, hydrolase, ligase, multifunctional enzyme, nucleotide-binding
• 由来する生物種: Escherichia coli
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 22352.96

構造登録者

Pai, C.-H.,Ko, T.-P.,Chiang, B.-Y.,Lin, C.-H.,Wang, A.H.-J. (登録日: 2009-06-05, 公開日: 2010-05-19, 最終更新日: 2024-12-25)

主引用文献

Chiang, B.-Y.,Chen, T.-C.,Pai, C.-H.,Chou, C.-C.,Chen, H.-H.,Ko, T.-P.,Hsu, W.-H.,Chang, C.-Y.,Wu, W.-F.,Wang, A.H.-J.,Lin, C.-H.
Protein S-thiolation by Glutathionylspermidine (Gsp): the role of Escherichia coli Gsp synthetASE/amidase in redox regulation
J.Biol.Chem., 285:25345-25353, 2010

PubMed Abstract: Certain bacteria synthesize glutathionylspermidine (Gsp), from GSH and spermidine. Escherichia coli Gsp synthetase/amidase (GspSA) catalyzes both the synthesis and hydrolysis of Gsp. Prior to the work reported herein, the physiological role(s) of Gsp or how the two opposing GspSA activities are regulated had not been elucidated. We report that Gsp-modified proteins from E. coli contain mixed disulfides of Gsp and protein thiols, representing a new type of post-translational modification formerly undocumented. The level of these proteins is increased by oxidative stress. We attribute the accumulation of such proteins to the selective inactivation of GspSA amidase activity. X-ray crystallography and a chemical modification study indicated that the catalytic cysteine thiol of the GspSA amidase domain is transiently inactivated by H(2)O(2) oxidation to sulfenic acid, which is stabilized by a very short hydrogen bond with a water molecule. We propose a set of reactions that explains how the levels of Gsp and Gsp S-thiolated proteins are modulated in response to oxidative stress. The hypersensitivities of GspSA and GspSA/glutaredoxin null mutants to H(2)O(2) support the idea that GspSA and glutaredoxin act synergistically to regulate the redox environment of E. coli.

PubMed: 20530482
DOI: 10.1074/jbc.M110.133363

実験手法

X-RAY DIFFRACTION (2.2 Å)