[Properties of the hexulose phosphate synthase of methylotrophic yeasts and bacteria]

Properties of hexulose phosphate synthase (HPS) were studied in extracts of the methanol assimilating yeast Candida methylica and the bacterium Arthrobacter globiformis B-175 assimilating methylated amines. HPS is an inducible enzyme which is localized in the soluble fraction of the cells. The effect of the pH of the reaction mixture, temperature, metal ions, and the concentration of substrates on the activity of HPS was studied. Properties of the enzyme were different in the yeast and the bacterium. The activity of HPS was strongly stimulated by ATP in C. methylica and was not affected in A. globiformis.