A Hexokinase Associated with Catabolite Repression in Pachysolen tannophilus

SUMMARY: A hexokinase (ATP:d-hexose 6-phosphotransferase; EC 2.7.1.1) associated with catabolite repression was isolated and purified from the yeast Pachysolen tannophilus. The enzyme phosphorylated d-fructose at a rate 1·5 times greater than that for d-glucose. The K m values for d-glucose and d-fructose were 0·36 and 2·28 mM, respectively. Neither xylose reductase nor xylitol dehydrogenase were subject to catabolite repression in mutants defective in this enzyme.