Crystallization and preliminary X-ray crystallographic studies of the ρ-class glutathione S-transferase from the Antarctic clam Laternula elliptica

Glutathione S-transferases are involved in phase II detoxification processes and catalyze the nucleophilic attack of the tripeptide glutathione on a wide range of endobiotic and xenobiotic electrophilic substrates. The ρ-class glutathione S-­transferase from Laternula elliptica was overexpressed in Escherichia coli, purified and crystallized with two substrates: glutathione and 1-chloro-2,4-dinitrobenzene (CDNB). Diffraction data were collected to 2.20 Å resolution for the glutathione-complex crystals and to 2.00 Å resolution for the CDNB-complex crystals using a synchrotron-radiation source. Both crystals belonged to the C-centred monoclinic space group C2. The unit-cell parameters for the CDNB-complex crystals were a = 89.66, b = 59.27, c = 55.45 Å, β = 124.52°. The asymmetric unit contained one molecule, with a corresponding V_M of 2.36 ų Da⁻¹ and a solvent content of 47.8%.