Phosphoglucomutase mutants of Neurospora sitophila and their relation to morphology.

Biochemical and genetic evidence is presented that the rg-1 and rg-2 genes control the structure of the two isozymes of phosphoglucomutase (Phosphoglucomutase I and II) in Neurospora silophila. Results of kinetic and gel filtration studies show that the two phosphoglucomutases may exist in vitro either as separate or as a single but complex molecular species depending on the ionic concentration. The complex phosphoglucomutase molecule is suggested to be the physiologically active form of the enzyme. The change in the enzyme structure is discussed in relation to the morphological change in the ragged mutant strains.