GST_N family, Class Phi subfamily; composed of plant-specific class Phi GSTs and related fungal and bacterial proteins. GSTs are cytosolic dimeric proteins involved in cellular detoxification by catalyzing the conjugation of glutathione (GSH) with a wide range of endogenous and xenobiotic alkylating agents, including carcinogens, therapeutic drugs, environmental toxins and products of oxidative stress. The GST fold contains an N-terminal TRX-fold domain and a C-terminal alpha helical domain, with an active site located in a cleft between the two domains. The class Phi GST subfamily has experience extensive gene duplication. The Arabidopsis and Oryza genomes contain 13 and 16 Phi GSTs, respectively. They are primarily responsible for herbicide detoxification together with class Tau GSTs, showing class specificity in substrate preference. Phi enzymes are highly reactive toward chloroacetanilide and thiocarbamate herbicides. Some Phi GSTs have other functions including transport of flavonoid pigments to the vacuole, shoot regeneration and GSH peroxidase activity.
Feature 1:GSH binding site (G-site) [chemical binding site]
Evidence:
Structure:1BYE; Zea mays GST-I with bound Atrazine-GSH conjugate; contacts at 3.5A to the GSH moiety
Structure:1GNW; Arabidopsis thaliana GST with bound hexyl-GSH; contacts at 3.5A to the GSH moiety
Comment:The GST active site is composed of a GSH binding site (G-site), common to all GSTs, and a xenobiotic binding site (H-site), which varies between different classes and isotypes. Residues from the N-terminal TRX-fold domain form the G-site while the H-site is comprised mainly of residues from the C-terminal alpha helical domain.
Jiyao W et al.(2023). "The conserved domain database in 2023.",