GST_N family, Ure2p-like subfamily; composed of the Saccharomyces cerevisiae Ure2p and related GSTs. Ure2p is a regulator for nitrogen catabolism in yeast. It represses the expression of several gene products involved in the use of poor nitrogen sources when rich sources are available. A transmissible conformational change of Ure2p results in a prion called [Ure3], an inactive, self-propagating and infectious amyloid. Ure2p displays a GST fold containing 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 N-terminal TRX-fold domain is sufficient to induce the [Ure3] phenotype and is also called the prion domain of Ure2p. In addition to its role in nitrogen regulation, Ure2p confers protection to cells against heavy metal ion and oxidant toxicity, and shows glutathione (GSH) peroxidase activity. Characterized GSTs in this subfamily include Aspergillus fumigatus GSTs 1 and 2, and Schizosaccharomyces pombe GST-I. GSTs are cytosolic dimeric proteins involved in cellular detoxification by catalyzing the conjugation of 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.
Feature 1:GSH binding site (G-site) [chemical binding site]
Evidence:
Structure:1K0D; Saccharomyces cerevisiae Ure2p 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.