Overexpression, crystallization and preliminary X-­ray crystallographic analysis of the RNA polymerase domain of primase from Streptococcus mutans strain UA159

Primase is the enzyme that synthesizes RNA primers on single-stranded DNA during normal DNA replication. In this study, the catalytic core domain of primase from Streptococcus mutans UA159 was overexpressed in Escherichia coli, purified and crystallized. Diffraction data were collected to 1.60 Å resolution using a synchrotron-radiation source. The crystal belonged to space group P4₁ or P4₃, with unit-cell parameters a = b = 52.63, c = 110.31 Å. The asymmetric unit is likely to contain one molecule, with a corresponding V_M of 1.77 Å³ Da^-1 and a solvent content of 30.7%.