In enzymology, a 6-phosphofructo-2-kinase (EC 188.8.131.52) is an enzyme that catalyzes the chemical reaction
ATP + beta-D-fructose 6-phosphate
ADP + beta-D-fructose 2,6-bisphosphate
Thus, the two substrates of this enzyme are ATP and beta-D-fructose 6-phosphate, whereas its two products are ADP and beta-D-fructose 2,6-bisphosphate.
This enzyme belongs to the family of transferases, specifically those transferring phosphorus-containing groups (phosphotransferases) with an alcohol group as acceptor. The systematic name of this enzyme class is ATP:beta-D-fructose-6-phosphate 2-phosphotransferase. Other names in common use include phosphofructokinase 2, 6-phosphofructose 2-kinase, 6-phosphofructo-2-kinase (phosphorylating), fructose 6-phosphate 2-kinase, and ATP:D-fructose-6-phosphate 2-phosphotransferase. This enzyme participates in fructose and mannose metabolism. The enzyme is important in the regulation of hepatic carbohydrate metabolism and is found in greatest quantities in the liver, kidney and heart. In mammals, several genes often encode different isoforms, each of which differs in its tissue distribution and enzymatic activity. The family described here bears a resemblance to the ATP-driven phospho-fructokinases, however, they share little sequence similarity, although a few residues seem key to their interaction with fructose 6-phosphate.
As of late 2007, 8 structures have been solved for this class of enzymes, with PDB accession codes 1BIF, 1K6M, 2AXN, 2BIF, 2DWO, 2DWP, 2I1V, and 3BIF.