Phosphofructokinase, a key regulatory enzyme in glycolysis, catalyzes the phosphorylation of fructose-6-phosphate to fructose-1,6-biphosphate. The members belong to a subfamily of the PFKA family (cd00363) and include eukaryotic ATP-dependent phosphofructokinases. These have evolved from the bacterial PFKs by gene duplication and fusion events and exhibit complex allosteric behavior.