Crystallization and preliminary X-ray characterization of aminopeptidase N from Escherichia coli.

A recombinant form of aminopeptidase N (molecular weight 99 kDa) from Escherichia coli was crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate as a precipitating agent. The crystals belong to the hexagonal space group P3(1)21, with unit-cell parameters a = b = 120.5, c = 171.0 angstroms. The crystals are most likely to contain one molecule in the asymmetric unit, with a V(M) value of 3.62 angstroms3 Da(-1). Diffraction data were collected to 2.0 angstroms resolution using Cu Kalpha radiation from a rotating-anode X-ray generator.