2.7.1.63 | purified recombinant enzyme, hanging drop vapour diffusion method, cyrstallization drop on a silconized coverslip by mixing of 0.003 ml protein solution consisting of 10 mg/ml protein in 10 mM glucose, and 10 mM potassium phosphate, pH 7.0, with an equal volume of mother liquor composed of 2.0 M ammonium sulfate, 2% v/v PEG 400, and 0.1 M HEPES, pH 8.0, cyrstals are soaked in several heavy atom derivative solutions containing 1 mM of UO2Ac2, 10 mM AgNO3, 10 mM GdCl2, 1 mM HgCl2, 10 mM K2Pt(CN)4, 2 mM TmCl2, or 1 mM EuCl3 in 0.1 M Tris-HCl at different pH-values, dependent on the heavy atom salt, for 20-60 min at 20°C, X-ray diffraction structure determiination and analysis at 3.0 A resolution, modeling |