GST_N family, Class Delta and Epsilon subfamily; 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. GSTs also show GSH peroxidase activity and are involved in the synthesis of prostaglandins and leukotrienes. 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 Delta and Epsilon subfamily is made up primarily of insect GSTs, which play major roles in insecticide resistance by facilitating reductive dehydrochlorination of insecticides or conjugating them with GSH to produce water-soluble metabolites that are easily excreted. They are also implicated in protection against cellular damage by oxidative stress.
Feature 1:GSH binding site (G-site) [chemical binding site]
Evidence:
Structure:1V2A; Anopheles dirus Class Delta GST with bound GSH sulfonic acid; contacts at 3.5A
Structure:1R5A; Anopheles dirus B Class Delta GST with bound GSH sulfonic acid; contacts at 3.5A
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.