Crystallization and preliminary X-ray study of a (2R,3R)-2,3-butanediol dehydrogenase from Bacillus coagulans 2-6

(2R,3R)-2,3-Butanediol dehydrogenase (R,R-BDH) from Bacillus coagulans 2-6 is a zinc-dependent medium-chain alcohol dehydrogenase. Recombinant R,R-BDH with a His₆ tag at the C-terminus was expressed in Escherichia coli BL21 (DE3) cells and purified by Ni²⁺-chelating affinity and size-exclusion chromatography. Crystals were grown by the hanging-drop vapour-diffusion method at 289 K. The crystallization condition consisted of 8%(v/v) Tacsimate pH 4.6, 18%(w/v) polyethylene glycol 3350. The crystal diffracted to 2.8 Å resolution in the orthorhombic space group P2₁2₁2₁, with unit-cell parameters a = 88.35, b = 128.73, c = 131.03 Å.