CRYSTALLIZATION OF 5-KETO-4-DEOXYURONATE ISOMERASE FROM ESCHERICHIA-COLI

5-keto-4-deoxyuronate isomerase from Escherichia coli has been crystal lized after partial purification. The isomerase was found to be enrich ed in preparations of an unrelated recombinant protein. Crystals of th e isomerase were obtained from two different precipitants despite the fact that the recombinant protein represented roughly 90% of the total protein present. The crystals diffract to 2.7 Angstrom resolution and are suitable for a structure determination. The role of the isomerase in E. coil is uncertain, as E. coil is not known to degrade the polys accharides which are potential sources of 5-keto-4-deoxyuronate.