Crystallization and preliminary X-ray crystallographic studies of glutamate racemase from Lactobacillus fermenti.

Glutamate racemase catalyzes the conversion of L-glutamic acid to D-glutamic acid and vice versa. Since D-glutamic acid is one of the essential amino acids present in peptidoglycan, glutamate racemase has been considered to be an attractive target for the design of new antibacterial drugs. Glutamate racemase from Lactobacillus fermenti has been crystallized by the hanging-drop vapour-diffusion method using polyethylene glycol 8000 as a precipitant. The crystals belong to the orthorhombic space group C222(1), with unit-cell parameters a = 98.32, b = 184.09, c = 45.99 A. The asymmetric unit contains one molecule, corresponding to a VM value of 1.84 A3 Da(-1). A complete data set has been collected from the native enzyme at 2.28 A resolution using a synchrotron-radiation source.