cl17181

Fructose/tagarose-bisphosphate aldolase class II. This family includes fructose-1,6-bisphosphate (FBP) and tagarose 1,6-bisphosphate (TBP) aldolases. FBP-aldolase is homodimeric and used in gluconeogenesis and glycolysis; the enzyme controls the condensation of dihydroxyacetone phosphate with glyceraldehyde-3-phosphate to yield fructose-1,6-bisphosphate. TBP-aldolase is tetrameric and produces tagarose-1,6-bisphosphate. There is an absolute requirement for a divalent metal ion, usually zinc, and in addition the enzymes are activated by monovalent cations such as Na+. Although structurally similar, the class I aldolases use a different mechanism and are believed to have an independent evolutionary origin.