Crystallization and preliminary X-ray diffraction studies of a bacterial flavohemoglobin protein

A flavohemoglobin protein (FHP) was isolated from Alcaligenes eutrophus and has been crystallized by vapor diffusion methods using PEG 3350 as precipitant. The crystals of the FAD- and heme-containing protein belong to the monoclinic space group P2(1) with unit cell parameters of 52.2 A, 85.8 A, 103.9 A, and 81.8 degrees corresponding to two molecules per asymmetric unit. The crystals diffract at least to a resolution of 2.0 A and are suitable for an X-ray structure analysis.