Crystallization and preliminary X‐ray analysis of NADH:rubredoxin oxidoreductase from Clostridium acetobutylicum

NADH:rubredoxin oxidoreductase (NROR), an O 2 ‐inducible protein, is a versatile electron donor for scavengers of O 2 and reactive oxygen species (ROS) in Clostridium acetobutylicum . Recombinant NROR was overexpressed in Escherichia coli and purified to homogeneity; it was subsequently crystallized using the sitting‐drop vapour‐diffusion method at 293 K. Preliminary crystallographic analysis revealed that the crystals belonged to space group P 4 1 22 or P 4 3 22, with unit‐cell parameters a = b = 98.6, c = 88.3 Å, and diffracted to 2.1 Å resolution. Assuming that the crystals contained one molecule per asymmetric unit, the Matthews coefficient was calculated to be 2.7 Å 3  Da −1 and the solvent content to be 54.1%.