Glutathione-dependent dehydroascorbate reductase (GSH-DHAR) catalyzes the reduction of dehydroascorbate to ascorbate using reduced glutathione as the electron donor. GSH-DHAR from spinach chloroplasts produced in Escherichia coli was crystallized by the hanging-drop vapour-diffusion method. The crystals were monoclinic, space group C2, with unit-cell parameters a = 98.25, b = 39.96, c = 106.86 A, beta = 110.46 degrees. The asymmetric unit contained two molecules, giving a crystal volume per enzyme mass (V(M)) of 2.06 A(3) Da(-1) and a solvent content of 40.3%. A full set of X-ray diffraction data were collected to 2.2 A Bragg spacing from three native crystals with an overall R(merge) of 6.5% and a completeness of 93.4%.