Conjugation of reduced glutathione to a wide number of exogenous and endogenous hydrophobic electrophiles. Has DDT dehydrochlorinase activity (By similarity). glutathione + RX = a halide anion + an S-substituted glutathione + H(+) 1,1,1-trichloro-2,2-bis(4-chlorophenyl)ethane = 1,1-dichloro-2,2-bis(4-chlorophenyl)ethylene + chloride + H(+) Homodimer. Belongs to the GST superfamily. Theta family.