Crystallization and preliminary X-ray analysis of SDR-type pyridoxal dehydrogenase from Mesorhizobium loti

Pyridoxal 4-dehydrogenase from Mesorhizobium loti MAFF303099 was overexpressed in Escherichia coli. The recombinant selenomethionine-substituted enzyme was purified and crystallized by the sitting-drop vapour-diffusion method using PEG 4000 as precipitant. Crystals grew in the presence of 0.45 mM NAD⁺. The crystals diffracted to 2.9 Å resolution and belonged to the monoclinic space group P2₁, with unit-cell parameters a = 86.20, b = 51.11, c = 91.73 Å, β = 89.36°. The calculated V_M values suggested that the asymmetric unit contained four molecules.