Crystallization and preliminary X‐ray analysis of the NADPH‐dependent 3‐quinuclidinone reductase from Rhodotorula rubra

( R )‐3‐Quinuclidinol is a useful compound that is applicable to the synthesis of various pharmaceuticals. The NADPH‐dependent carbonyl reductase 3‐quinuclidinone reductase from Rhodotorula rubra catalyzes the stereospecific reduction of 3‐quinuclidinone to ( R )‐3‐quinuclidinol and is expected to be utilized in industrial production of this alcohol. 3‐Quinuclidinone reductase from R. rubra was expressed in Escherichia coli and purified using Ni‐affinity and ion‐exchange column chromatography. Crystals of the protein were obtained by the sitting‐drop vapour‐diffusion method using PEG 8000 as the precipitant. The crystals belonged to space group P 4 1 2 1 2, with unit‐cell parameters a = b = 91.3, c = 265.4 Å, and diffracted X‐rays to 2.2 Å resolution. The asymmetric unit contained four molecules of the protein and the solvent content was 48.4%.