Characterization of d-xylose reductase, XyrB, from Aspergillus niger

Abstract d -xylose reductase is a member of the aldo-keto reductase family, and is involved in d -xylose and l -arabinose conversion through the Pentose Catabolic Pathway (PCP) in fungi. In this study, we biochemically characterized a newly identified second d -xylose reductase (XyrB) from Aspergillus niger. This NADPH-dependent reductase is able to efficiently convert d -xylose and l -arabinose, and it has the highest affinity for these sugars of all currently known fungal pentose reductases. A combination of biochemical data, transcriptomics and phylogenetic analysis further illustrated the role of XyrB in the PCP. Enzymes: D-xylose reductase (EC 1.1.1.307), L-arabinose reductase (EC 1.1.1.21).