Mutant alleles of the gene PFKZ have been obtained that alter the sensitivity to ATP inhibition of the soluble yeast phosphofructokinase. One of the alleles makes the enzyme sensitive to micromolar concentrations of ATP. Intragenic revertants of PFK2 mutants confirm that the PFK2 gene determines not only the regulatory properties of the soluble enzyme but also the catalytic activity of particulate phosphofructokinase.

Mutants of Saccharomyces cerevisiae lacking the particulate phosphofructokinase define at least four unlinked genes, PFK2, PFK3, PFK4 and PFK5. A structural role of PFK2 is indicated. Mutations in the other three have pleiotropic effects.