1.14.14.16 | purified recombinant His-tagged CYP21A2 mutant T241R/L442A in complex with substrate 17-hydroxyprogesterone, hanging drop vapor diffusion method, 0.2 mM protein in 50 mM potassium phosphate, pH 7.4, 20% glycerol, 0.1 mM DTT, 0.1 mM EDTA, 0.25% Cymal 5, and 50 mM NaCl, is mixed with 0.4 mM, containing 2% v/v C2H5OH, and 5-15% w/v PEG 3350, 0.5 M ammonium sulfate, and 0.1 M HEPES, pH 7.0, 20°C, few days, X-ray diffraction structure determination and analysis at 3.0 A resolution |