Crystallization and preliminary X-ray diffraction studies of catalase–peroxidase fromSynechococcusPCC 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 P4(1)2(1)2 or P4(3)2(1)2, with unit-cell parameters a = b = 109.3, c = 202.0 A. The calculated V(M) value based on a dimer in the asymmetric unit was 1.9 A(3) Da(-1). A native data set was collected to 2.3 A resolution from a frozen crystal using synchrotron radiation at SPring-8.