CRYSTALLIZATION AND PRELIMINARY CRYSTALLOGRAPHIC DATA FOR CLASS-I DEOXYRIBOSE-5-PHOSPHATE ALDOLASE FROM ESCHERICHIA-COLI - AN APPLICATION OF REVERSE SCREENING

X-ray quality crystals of class I deoxyribose-5-phosphate aldolase fro m Escherichia coli have been obtained for the unliganded enzyme and in complex with its substrate, 2 deoxyribose-5-phosphate. The enzyme cat alyzes the reversible cleavage of 2-deoxyribose-5-phosphate to acetald ehyde and D-glyceraldehyde-3-phosphate. The unliganded and complex cry stals are prismatic long rods and belong to the orthorhombic space gro up P2(1)2(1)2(1) with cell dimensions a = 183.1 Angstrom, b = 61.4 Ang strom c = 49.3 Angstrom and a = 179.2 Angstrom, b = 60.5, Angstrom, c = 49.1 Angstrom, respectively. Two molecules in the asymmetric unit ar e related by a noncrystallographic 2-fold axis. The crystals are stabl e in the X-ray beam and diffract to at least 2.6 Angstrom. A new metho d, reverse screening, designed to minimize protein utilization during the screening process was used to determine supersaturation and crysta llization conditions. (C) 1995 Wiley-Liss, Inc.