Purification, crystallization and preliminary X-ray crystallographic analysis of xylose reductase from Candida tropicalis

Abstract

Xylose reductase (XR), which requires NADPH as a co-substrate, catalyzes the reduction of D-xylose to xylitol, which is the first step in the metabolism of D-xylose. The detailed three-dimensional structure of XR will provide a better understanding of the biological significance of XR in the efficient production of xylitol from biomass. XR of molecular mass 36.6 kDa from Candida tropicalis was crystallized using the hanging-drop vapour-diffusion method. According to X-ray diffraction data from C. tropicalis XR crystals at 2.91 angstrom resolution, the unit cell belongs to space group P3(1) or P3(2). Preliminary analysis indicated the presence of four XR molecules in the asymmetric unit, with 68.0% solvent content.