Crystallization and preliminary crystallographic analysis of the autoinhibited form of the tandem SH3 domain of p47^phox

p47^phox is a cytosolic component of the phagocyte NADPH oxidase, which is responsible for the production of the superoxide which kills invasive microorgamisms. A recombinant form of a histidine-tagged tandem SH3 domain of the p47^phox-containing polybasic autoinhibited region was expressed in Escherichia coli and purified and crystallized by the sitting-drop vapour-diffusion method at 293 K using polyethylene glycol 6000 as a precipitant. Diffraction data were collected to 2.15 Å resolution at 100 K using synchrotron radiation. The crystal belongs to space group P4 ₁2₁2 or P4₃2₁2, with unit-cell parameters a = 100.02, c = 44.94 Å. The presence of one molecule per asymmetric unit gives a crystal volume per protein mass (V_M) of 2.6 ų Da^-1 and a solvent content of 52% by volume.