Crystallization and preliminary crystallographic data of ribonucleotide reductase protein B2 from Escherichia coli

The B2 subunit of ribonucleotide reductase from Escherichia coli has been crystallized from ammonium sulfate solutions at pH 6.0. Crystals grew as orthorhombic plates with cell dimensions a = 58 A, b = 73 A, and c = 205 A. The asymmetric unit probably contains one B2 dimer of molecular weight 2 X 43,000. The packing of molecules in the crystals is compatible with an elongated shape of the dimer. The crystals diffract to 2.5 A and are suitable for structural work.