2.7.12.2 | purified recombinant apo MAP2K4-KD or in complex with ANP, 15 mg/ml protein in a solution containing 20 mM Tris-HCl, pH 7.5, 100 mM NaCl, 10% glycerol and 10 mM DTT for the apoenzyme, and 2 mM ANP and MgCl2 additional for the npMAP2K4/ANP complex, mixing with reservoir solution containing 0.2 M ammonium acetate, 22-25% w/v PEG 3350 and 0.1 M HEPESNaOH, pH 7.0, 20°C, X-ray diffraction structure determination and analysis at 3.5 A resolution |