Crystallization and preliminary X-ray crystallographic analysis of the unusual ferritin from Listeria innocua

Single crystals of ferritin extracted from Listeria innocua have been obtai ned by the vapour-diffusion method using PEG 1000 as precipitant. The cryst als are orthorhombic, space group P2(1)2(1)2(1). with unit-cell dimensions a = 87.7, b = 137.5, c = 173.1 Angstrom. The crystals diffract to 2.9 Angst rom resolution on a rotating-anode X-ray source and to 2.35 Angstrom resolu tion on a synchrotron X-ray source. The asymmetric unit contains one molecu le formed by 12 subunits, corresponding to a packing density of 2.41 Angstr om(3) Da(-1).