| X-RAY DIFFRACTION |
7.8 |
293 |
After purification, OAT was buffer exchanged into the crystallization buffer (50 mM Tricine pH 7.8) supplied supplemented with 1 mM 2-ketoglutarate. The protein was concentrated to 6.5 mg/mL. Previously reported crystallization conditions were optimized using the hanging drop vapor diffusion method by varying PEG 6000 (8-12%), NaCl (100-250 mM), and glycerol (0%-10%) with 100 mM Tricine pH 7.8 was being kept constant as the buffer. For each hanging drop, 2 uL of protein solution was mixed with an equal volume of well solution and 0.5 uL of ligand. The crystals with the best morphology and size grew in a final condition containing 12% PEG 6000, 200 mM NaCl, 10% glycerol, and 100 mM Tricine pH 7.8. Crystals were transferred to a cryo-protectant solution (well solution supplemented with 30% glycerol) and flash-frozen in liquid nitrogen |
