Crystallization and preliminary X-ray diffraction analysis of diaminopimelate epimerase from Escherichia coli.

Diaminopimelate (DAP) epimerase (EC 5.1.1.7) catalyzes the penultimate step of lysine biosynthesis in bacteria and plants, converting L,L-diaminopimelate to meso-diaminopimelate. Here, the cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of DAP epimerase from Escherichia coli are presented. Crystals were obtained in space group P4(1)2(1)2 and diffracted to 2.0 A resolution, with unit-cell parameters a = b = 89.4, c = 179.6 A. Molecular replacement was conducted using Bacillus anthracis DAP epimerase as a search model and showed the presence of two molecules in the asymmetric unit, with an initial R(free) of 0.456 and R(work) of 0.416.