FUNCTIONAL COMPLEMENTATION OF YEAST PHOSPHOFRUCTOKINASE MUTANTS BY THE NON-ALLOSTERIC ENZYME FROM DICTYOSTELIUM-DISCOIDEUM

Phosphofructokinase (PFK) from yeast has been replaced by the non-allo steric isozyme from the slime mold Dictyostelium discoideum. This has been achieved by overexpression of the latter in a PFK-deficient strai n of Saccharomyces cerevisiae under the control of the PFK2 promoter. Transformants complemented the glucose-negative growth phenotype exhib iting generation times on glucose-containing media similar to those of an untransformed strain being wild-type for yeast PFK genes. The PFK produced reacted with an antibody against D. discoideum PFK. It exhibi ted the same subunit size, quaternary structure and kinetic parameters than those of the wild-type enzyme, and was also devoid of specific r egulatory properties.