   1.13.11.9 | hanging-drop vapor-diffusion method at 20°C, crystal structure for the resting form of the enzyme (NicX), as well as a complex structure wherein 2,5-hydroxy-pyridine and N-formylmaleamic acid are trapped in different subunits. The resting state structure displays an octahedral coordination for Fe(II) with two histidine residues (His265 and His318), a serine residue (Ser302), a carboxylate ligand (Asp320), and two water molecules. 2,5-Hydroxy-pyridine does not bind as a ligand to Fe(II), yet its interactions with Leu104 and His105 function to guide and stabilize the substrate to the appropriate position to initiate the reaction |
| 1.13.11.9 | purified recombinant NicX, hanging drop vapour diffusion method, 0.001 ml of 14 mg/ml protein in 20 mM HEPES pH 7.5, 0.1 M NaCl, and 2 mM DTT, is mixed with 0.001 ml of reservoir solution, containing 22% w/v PEG 4000, 0.1 M sodium acetate and 0.1 M HEPES pH 7.5, 2 mM DTT, and with 1 ml 50 mM EDTA, 18°C, method optimization, X-ray diffraction structure determination and analysis at 2.0 A resolution |
