Crystallization and preliminary X-ray diffraction studies of catalase-peroxidase from Synechococcus PCC 7942

The recombinant catalase-peroxidase of Synechococcus PCC 7942 overexpressed in Escherichia coli was purified and crystallized by the hanging-drop vapour-diffusion method using sodium formate as a precipitant. The crystals belonged to the tetragonal space group P4₁2₁2 or P4₃2₁2, with unit-cell parameters a = b = 109.3, c = 202.0 Å. The calculated V_M value based on a dimer in the asymmetric unit was 1.9 Å³ Da^-1. A native data set was collected to 2.3 Å resolution from a frozen crystal using synchrotron radiation at SPring-8.