4.4.1.22 | analysis of seleno-methionine-labeled enzyme GFA X-ray crystal structures from Paracoccus denitrificans, PDB IDs 1X6M and 1XA8. Crystallization of purified recombinant detagged enzyme, free or as Gfa-glutathione complex, vapor diffusion by mixing 0.002 ml of 9 mg/ml protein in 20 mM HEPES, pH 7.0, and 100 mM NaCl with 0.002 ml of reservoir solution containing 2.0-2.1 M (NH4)2SO4, 4% PEG 400, and 0.1 M HEPES, pH 7.4, for the enzyme complex crystals, 10 mM of the reduced form of L-glutathione and 5 mM 2-mercaptoethanol are added to the reservoir solution, X-ray diffraction structure determination and analysis at 2.35 A resolution |