A GENE HOMOLOGOUS TO THAT ENCODING UDP GALACTOSE-4-EPIMERASE IS INDUCIBLE BY XYLOSE IN THE YEAST PACHYSOLEN-TANNOPHILUS

Using DNA sequencing, we have identified a fragment of genomic DNA fro m Pachysolen tannophilus that is homologous to the GAL10 gene in yeast s and galE gene in bacteria, both encoding the UDP galactose-4-epimera se (EC 5.1.3.2). This gene (designated PtGAL10) is equally efficiently inducible by D-galactose (a hexose) and D-xylose (a pentose). The enc oded protein shows the highest similarity to the homologous Kluyveromy ces lactis protein. This includes the N-terminal domain that is not pr esent in homologous polypeptides from other organisms.