2.8.3.18 | native and C-terminally His6-tagged wild-type enzymes in complexes including freeze-trapped acetylglutamyl anhydride and glutamyl-CoA thioester adducts, hanging drop vapor diffusion method, mixing of 0.002 ml of protein solution containing 5.6 mg/ml AarC in 45 mM potassium phosphate, pH 8.0, 90 mM potassium chloride, and 2 mM CoA or 6.0 mg/ml His6-tagged AarC in 45 mM Tris-HCl, pH 8.0, 90 mM potassium chloride, and 2 mM CoA, with 0.002 ml of reservoir solution containing 0.8-1.0 M sodium citrate, 0.1 M imidazole, pH 8.2, and 25 mM 2-mercaptoethanol for orthorhombic crystals or 1.7-2.0 M ammonium sulfate, 0.2 M sodium chloride, 0.1 M sodium cacodylate, pH 6.5, and 25 mM 2-mercaptoethanol for hexagonal crystals, room temperature of about 22°C, X-ray diffraction structure determination and analysis |