2.1.1.201 | purified enzyme in apoform and in complex with S-adenosyl-L-methionine, hanging drop vapour diffusion method, mixing of 0.003 ml of 5 mg/ml protein and 5 mM DTT with 0.001 ml reservoir solution containing 20% w/v 2-propanol, 20% w/v PEG 4000, 0.1 M sodium citrate tribasic, pH 5.6, for the apoenzyme, and 20% w/v PEG 3350, 0.2 M ammonium citrate tribasic, pH 7.0, for the enzyme complex, equilibration against 0.1 ml reservoir solution, 1-7 days, X-ray diffraction structure determination and analysis at 2.2-2.4 A resolution, single-wavelength anomalous dispersion phasing method |