Overexpression, crystallization, and preliminary X-ray crystallographic analysis of the alanine racemase from...

Alanine racemase, a bacterial enzyme belonging to the fold-type III group of pyridoxal 5'-phosphate (PLP)-dependent enzymes, has been shown to catalyze the interconversion between L- and D-alanine. The alanine racemase from the pathogenic bacterium Enterococcus faecalis v583 has been overexpressed in E. coli and was shown to crystallize an enzyme at 295 K, using polyethylene glycol (PEG) 8000 as a precipitant. X-ray diffraction data to 2.5 A has been collected using synchrotron radiation. The crystal is a member of the orthorhombic space group, C222(1), with unit cell parameter of a=94.634, b=156.516, c=147.878 A, and alpha=beta;=gamma=90 degrees. Two or three monomers are likely to be present in the asymmetric unit, with a corresponding Vm of 3.38 A3 Da(-1) and 2.26 A Da(-1) and a solvent content of 63.7% and 45.5%, respectively.