Production, crystallization and preliminary X-ray crystallographic studies of the bacteriophage φ12 packaging motor

The hexameric ATPase P4 from bacteriophage phi12 is responsible for packaging single-stranded genomic precursors into the viral procapsid. P4 was overexpressed in Escherichia coli and purified. Crystals of native and selenomethionine-derivatized P4 have been obtained that belong to space group I222, with half a hexamer in the asymmetric unit and unit-cell parameters a=105.0, b=130.5, c=158.9 Angstrom. A second crystal form of different morphology can occur in the same crystallization drop. The second form belongs to space group P1, with four hexamers in the asymmetric unit and unit-cell parameters a=114.9, b=125.6, c=153.9 Angstrom, alpha=90.1, beta=91.6, gamma=90.4degrees. Synchrotron X-ray diffraction data have been collected for the I222 and P1 crystal forms to 2.0 and 2.5 Angstrom resolution, respectively.