GST_N family, Class Omega 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. 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. Class Omega GSTs show little or no GSH-conjugating activity towards standard GST substrates. Instead, they catalyze the GSH dependent reduction of protein disulfides, dehydroascorbate and monomethylarsonate, activities which are more characteristic of glutaredoxins. They contain a conserved cysteine equivalent to the first cysteine in the CXXC motif of glutaredoxins, which is a redox active residue capable of reducing GSH mixed disulfides in a monothiol mechanism. Polymorphisms of the class Omega GST genes may be associated with the development of some types of cancer and the age-at-onset of both Alzheimer's and Parkinson's diseases.
Feature 1:GSH binding site (G-site) [chemical binding site]
Evidence:
Structure:1EEM; Human class Omega GST with bound GSH; 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.
Jiyao W et al.(2023). "The conserved domain database in 2023.",