Glutathione S-transferase that catalyzes the nucleophilic attack of the sulfur atom of glutathione on the electrophilic groups of a wide range of exogenous and endogenous compounds (PubMed:9606968). Involved in the formation of glutathione conjugates of both prostaglandin A2 (PGA2) and prostaglandin J2 (PGJ2). It also catalyzes the isomerization of D5-androstene-3,17-dione (AD) into D4-androstene-3,17-dione and may therefore play an important role in hormone biosynthesis. Through its glutathione-dependent peroxidase activity toward the fatty acid hydroperoxide (13S)-hydroperoxy-(9Z,11E)-octadecadienoate/13-HPODE it is also involved in the metabolism of oxidized linoleic acid (By similarity). glutathione + RX = a halide anion + an S-substituted glutathione + H(+) glutathione + prostaglandin A2 = prostaglandin A2-S-(R)-glutathione glutathione + prostaglandin J2 = prostaglandin J2-S-(R)-glutathione (13S)-hydroperoxy-(9Z,11E)-octadecadienoate + 2 glutathione = (13S)-hydroxy-(9Z,11E)-octadecadienoate + glutathione disulfide + H2O androst-5-ene-3,17-dione = androst-4-ene-3,17-dione Homodimer. Expressed in the liver, skin and kidney. Induced in the liver by beta-naphthoflavone (BNF) and 2(3)-t-butyl-4-hydroxyanisole (BHA). Belongs to the GST superfamily. Alpha family.