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-diff usion method, using polyethylene glycol and ammonium acetate as precip itants. The crystals were resistant to X-ray radiation damage and diff racted to more than 2.0 Angstrom resolution, The diffraction pattern i ndicated that the crystals belong to the orthorhombic system, space gr oup P2(1)2(1)2(1), with unit-cell dimensions of a=78.1, b=97.2, and c= 100.7 Angstrom. It is supposed that the asymmetric unit consists of tw o N-acyl-D-glucosamine 2-epimerase molecules, Collection of data on th e native crystals indicated that they are suitable for X-ray structura l analysis.