3.4.24.58	purified enzyme by the sitting drop vapor diffusion method, mixing of 0.001 ml of protein solution with 0.001 ml of reservoir solution, containing 0.1M calcium acetate, 0.1M sodium cacodylate, 10% PEG 8000, pH 6.5, supplemented with one fifth volume of 10% PEG 3350, and equilibration against 1 ml of reservoir solution at 20°C, one week, cryoprotection with 15% 2-methyl-2,4-pentanediol in reservoir solution, X-ray diffraction structure determination and analysis at 2.9 A resolution, modeling	683476