An allosteric enzyme that regulates glycolysis by catalysing the transfer of a phosphate group from ATP to fructose-6-phosphate to yield fructose-1,6-bisphosphate. D-tagatose- 6-phosphate and sedoheptulose-7-phosphate also are acceptors. UTP, CTP, and ITP also are donors. In human phosphofructokinase-1, three types of subunits have been identified. They are muscle type phosphofructokinase-1; liver type phosphofructokinase-1; and type C phosphofructokinase-1; found in platelets, brain, and other tissues.