Crystallization and preliminary X-ray diffraction studies of N-acyl-D-glucosamine 2-epimerase from porcine kidney.

N-Acyl-D-glucosamine 2-epimerase from porcine kidney, which was cloned and expressed in Escherichia coli, was crystallized by the vapor-diffusion method, using polyethylene glycol and ammonium acetate as precipitants. The crystals were resistant to X-ray radiation damage and diffracted to more than 2.0 A resolution. The diffraction pattern indicated that the crystals belong to the orthorhombic system, space group P2(1)2(1)2(1), with unit-cell dimensions of a = 78.1, b = 97.2, and c = 100.7 A. It is supposed that the asymmetric unit consists of two N-acyl-D-glucosamine 2-epimerase molecules. Collection of data on the native crystals indicated that they are suitable for X-ray structural analysis.