An allosteric enzyme that regulates glycolysis by catalyzing 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 PHOSPHOFRUCTOKINASE-1, MUSCLE TYPE; PHOSPHOFRUCTOKINASE-1, LIVER TYPE; and PHOSPHOFRUCTOKINASE-1, TYPE C; found in platelets, brain, and other tissues.