Purification, crystallization and preliminary X-ray diffraction studies of a putative UDP-N-acetyl-d-mannosamine dehydrogenase from Pyrococcus horikoshii OT3

A putative UDP-N-acetyl-d-mannosamine dehydrogenase from P. horikoshii OT3 has been crystallized in space group P2₁, with unit-cell parameters a = 80.28, b = 69.24, c = 83.10 Å, β = 114.4°. X-ray diffraction data have been collected to 1.80 Å resolution. A putative UDP-N-acetyl-d-mannosamine dehydrogenase from Pyrococcus horikoshii OT3, an essential enzyme for polysaccharide biosynthesis, has been overexpressed in Escherichia coli and purified. Crystals were obtained using the oil-microbatch method at 291 K. A native data set extending to 1.8 Å resolution has been collected and processed in space group P2₁. Assuming the presence of a dimer in the asymmetric unit, the V_M value is calculated to be 2.3 ų Da⁻¹, which is consistent with the result of a dynamic light-scattering experiment that shows a dimeric state of the protein in solution