Crystallization and preliminary X-ray study of AMP nucleosidase

Adenosine-5'-monophosphate nucleosidase from Escherichia coli has been crystallized in the presence of its strong competitive inhibitor formycin 5'-monophosphate and its allosteric activator adenosine 5'-triphosphate. Crystals are tetragonal bipyramids which grow to 1.2 mm in the longest dimension, are resistant to radiation damage, and diffract to a resolution of 3.5 Å. The space group is P4₁2₁2 or P4₃2₁2, and the unit cell dimensions are a = 120.1 Å and c = 243.7 Å. The asymmetric unit is estimated to contain four subunits of 52,000 daltons. The crystals appear suitable for single crystal x-ray structure investigation.