Catalyzes the phosphorylation of D-fructose 6-phosphate to fructose 1,6-bisphosphate by ATP, the first committing step of glycolysis (PubMed:22923583). Negatively regulates the phagocyte oxidative burst in response to bacterial infection by controlling cellular NADPH biosynthesis and NADPH oxidase-derived reactive oxygen species. Upon macrophage activation, drives the metabolic switch toward glycolysis, thus preventing glucose turnover that produces NADPH via pentose phosphate pathway (By similarity). ATP + beta-D-fructose 6-phosphate = ADP + beta-D-fructose 1,6-bisphosphate + H(+) Allosterically activated by ADP, AMP, or fructose 2,6-bisphosphate, and allosterically inhibited by ATP or citrate. GlcNAcylation by OGT overcomes allosteric regulation. Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-phosphate and glycerone phosphate from D-glucose: step 3/4. Homo- and heterotetramers (By similarity). Phosphofructokinase (PFK) enzyme functions as a tetramer composed of different combinations of 3 types of subunits, called PFKM (where M stands for Muscle), PFKL (Liver) and PFKP (Platelet). The composition of the PFK tetramer differs according to the tissue type it is present in. In muscles, it is composed of 4 PFKM subunits (also called M4). In the liver, the predominant form is a tetramer of PFKL subunits (L4). In erythrocytes, both PFKM and PFKL subunits randomly tetramerize to form M4, L4 and other combinations (ML3, M2L2, M3L). The kinetic and regulatory properties of the tetrameric enzyme are dependent on the subunit composition, hence can vary across tissues (Probable). GlcNAcylation at Ser-529 by OGT decreases enzyme activity, leading to redirect glucose flux through the oxidative pentose phosphate pathway. Glycosylation is stimulated by both hypoxia and glucose deprivation. In human PFK exists as a system of 3 types of subunits, PFKM (muscle), PFKL (liver) and PFKP (platelet) isoenzymes. Glycosylation may play a role in cancer cell proliferation: inhibition of 6-phosphofructokinase activity and subsequent redirection of the glucose flux through the oxidative pentose phosphate pathway confers a selective growth advantage on cancer cells. Moreover GlcNAcylation is observed in multiple cancer cell lines and tissue samples and GlcNAcylation leads to larger xenografts tunors in mice (PubMed:22923583). Belongs to the phosphofructokinase type A (PFKA) family. ATP-dependent PFK group I subfamily. Eukaryotic two domain clade 'E' sub-subfamily.