Purification and preliminary X-ray crystallographic studies of recombinant L-ribulose-5-phosphate 4-epimerase from Escherichia coli.

The araD gene from Escherichia coli, coding for L-ribulose-5-phosphate 4-epimerase, was overexpressed and the resulting enzyme was purified to homogeneity. Crystals of L-ribulose-5-phosphate 4-epimerase, obtained with 4.0 M sodium formate as precipitant, belong to space group P4212 with unit cell dimensions a = b = 107.8 A and c = 281.4 A and diffract to at least 2.2 A resolution. Density measurements of these crystals are consistent with eight subunits in the asymmetric unit.