Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles (PubMed:22082028). May be involved in the detoxification of metabolites produced during cellular division and morphogenesis (PubMed:1445191, PubMed:12547198). glutathione + RX = a halide anion + an S-substituted glutathione + H(+) Homodimer. Expressed throughout development with highest levels being observed in nonfeeding stages, i.e. during embryonic and pupal development. Belongs to the GST superfamily. Sigma family.