3.7.1.24 | purified wild-type and selenomethionine-labeled enzymes, hanging drop vapor diffusion technique, mixing of 0.001 ml of 20 mg/ml protein sample with an equal volume of the reservoir solution containing 20% PEG 4000, 17% isopropyl alcohol, and 0.1 M sodium citrate, pH 5.6, crystals appear in 1-2 days and reach maximum size in 1 week, at 16°C, X-ray diffraction structure determination and analysis at 2.0 A resolution, MAD phasing method, modeling |