Using DNA sequencing, we have identified a fragment of genomic DNA from Pachysolen tannophilus that is homologous to the GAL10 gene in yeasts and galE gene in bacteria, both encoding the UDP galactose-4-epimerase (EC 5.1.3.2). This gene (designated PtGAL10) is equally efficiently inducible by D-galactose (a hexose) and D-xylose (a pentose). The encoded protein shows the highest similarity to the homologous Kluyveromyces lactis protein. This includes the N-terminal domain that is not present in homologous polypeptides from other organisms.