6.2.1.25 | purified recombinant His-tagged wild-type enzyme, hanging drop vapor diffusion method, mixing of 0.002 ml of 17.5 mg/ml protein in 20 mM Tris, pH 8.0, with or without 4 equiv carboxylic acid ligand, e.g. 2-fluorobenzoate, 2-methylbenzoate, 3-furoate, and thiophene-2-carboxylate, with 0.002 ml of reservoir solution containing 0.1 M Tris-HCl, pH 7.0, and 15% w/v PEG 3350, best crystals grew in a pH range from pH 6.5-7.5, X-ray diffraction structure determination and analysis |