Structure of Escherichia coli ribonucleotide reductase R2 in space group P6₁22

A new crystal form of wild-type ribonucleotide reductase R2 from Escherichia coli was obtained. Crystals grow in space group P6₁22 with one R2 monomer in the asymmetric unit. A twofold crystallographic symmetry axis generates the physiological dimeric form of R2. Co-crystallization with CoCl₂ or MnCl₂ results in full occupancy of the dinuclear metal site. The structure of the Mn^II-loaded form was determined to 2.6 Å resolution by molecular replacement. The crystallization conditions, backbone conformation, crystal-packing interactions and metal centers are compared with those of previously determined crystal forms.