– 6-phosphofructokinase, muscle type is a muscle-type isozyme that in humans is encoded by the PFKM gene. It belongs to the phosphofructokinase family and Two domains subfamily. PFKM functions as subunits of the mammalian tetramer phosphofructokinase, which catalyzes the phosphorylation of fructose-6-phosphate to fructose-1,6-bisphosphate. PFK1 converts fructose 6-phosphate and ATP into fructose 1,6-bisphosphate (through PFK-1), fructose 2,6-bisphosphate (through PFK-2) and ADP.