Purification, crystallization and preliminary X‐ray crystallographic analysis of diaminopimelate epimerase from Acinetobacter baumannii

The meso isomer of diaminopimelate ( meso ‐DAP) is a biosynthetic precursor of L‐lysine in bacteria and plants, and is a key component of the peptidoglycan layer in the cell walls of Gram‐negative and some Gram‐positive bacteria. Diaminopimelate epimerase (DapF) is a pyridoxal‐5′‐phosphate‐independent racemase which catalyses the interconversion of (6 S ,2 S )‐2,6‐diaminopimelic acid (LL‐DAP) and meso ‐DAP. In this study, DapF from Acinetobacter baumannii was overexpressed in Escherichia coli strain SoluBL21, purified and crystallized using a vapour‐diffusion method. A native crystal diffracted to a resolution of 1.9 Å and belonged to space group P 3 1 or P 3 2 , with unit‐cell parameters a  =  b  = 74.91, c = 113.35 Å, α = β = 90, γ = 120°. There were two molecules in the asymmetric unit.