Crystallization and preliminary X-ray analysis of a microbial superantigen staphylococcal enterotoxin C2

High yields of staphylococcal enterotoxin C2, from Staphylococcus aureus, have been purified using dye ligand chromatography. Crystals suitable for X-ray diffraction work were obtained by vapour diffusion using ammonium sulphate and polyethylene glycol as precipitants. They belong to the tetragonal space group P4(1)22 with unit cell dimensions a = b = 43.2 A and c = 290.9 A with one molecule per asymmetric unit. The crystals diffract to at least 2.8 A resolution and are suitable for three-dimensional X-ray structural analysis.