6F05

ARABIDOPSIS THALIANA GSTF9, GSO3 BOUND

Summary for 6F05

• Entry DOI: 10.2210/pdb6f05/pdb
• Related: 6EZY 6F01
• Descriptor: Glutathione S-transferase F9, GLUTATHIONE SULFONIC ACID, GLYCEROL, ... (5 entities in total)
• Functional Keywords: transferase, phi class, peroxidase, gso3
• Biological source: Arabidopsis thaliana (Mouse-ear cress)
• Total number of polymer chains: 10
• Total formula weight: 246019.32

Authors

Tossounian, M.A.,Wahni, K.,VanMolle, I.,Vertommen, D.,Rosado, L.,Messens, J. (deposition date: 2017-11-17, release date: 2018-08-15, Last modification date: 2024-01-17)

Primary citation

Tossounian, M.A.,Wahni, K.,Van Molle, I.,Vertommen, D.,Astolfi Rosado, L.,Messens, J.
Redox-regulated methionine oxidation of Arabidopsis thaliana glutathione transferase Phi9 induces H-site flexibility.
Protein Sci., 28:56-67, 2019

PubMed Abstract: Glutathione transferase enzymes help plants to cope with biotic and abiotic stress. They mainly catalyze the conjugation of glutathione (GSH) onto xenobiotics, and some act as glutathione peroxidase. With X-ray crystallography, kinetics, and thermodynamics, we studied the impact of oxidation on Arabidopsis thaliana glutathione transferase Phi 9 (GSTF9). GSTF9 has no cysteine in its sequence, and it adopts a universal GST structural fold characterized by a typical conserved GSH-binding site (G-site) and a hydrophobic co-substrate-binding site (H-site). At elevated H O concentrations, methionine sulfur oxidation decreases its transferase activity. This oxidation increases the flexibility of the H-site loop, which is reflected in lower activities for hydrophobic substrates. Determination of the transition state thermodynamic parameters shows that upon oxidation an increased enthalpic penalty is counterbalanced by a more favorable entropic contribution. All in all, to guarantee functionality under oxidative stress conditions, GSTF9 employs a thermodynamic and structural compensatory mechanism and becomes substrate of methionine sulfoxide reductases, making it a redox-regulated enzyme.

PubMed: 29732642
DOI: 10.1002/pro.3440

Experimental method

X-RAY DIFFRACTION (2.2 Å)