InterPro domain: IPR000741

Fructose-bisphosphate aldolase ( 4.1.2.13 ) [ 1 , 2 ] is a glycolytic enzyme that catalyses the reversible aldol cleavage or condensation of fructose-1,6-bisphosphate into dihydroxyacetone-phosphate and glyceraldehyde 3-phosphate. There are two classes of fructose-bisphosphate aldolases with different catalytic mechanisms: class I enzymes [ 3 ] do not require a metal ion, and are characterised by the formation of a Schiff base intermediate between a highly conserved active site lysine and a substrate carbonyl group, while the class II enzymes require an active-site divalent metal ion. This entry represents the class I enzymes.

In vertebrates, three forms of this enzyme are found: aldolase A is expressed in muscle, aldolase B in liver, kidney, stomach and intestine, and aldolase C in brain, heart and ovary. The different isozymes have different catalytic functions: aldolases A and C are mainly involved in glycolysis, while aldolase B is involved in both glycolysis and gluconeogenesis. Defects in aldolase A cause Glycogen storage disease 12 (GSD12) [ 4 ], while defects in aldolase B result in hereditary fructose intolerance [ 5 ].

1. The fructose-1,6-bisphosphate aldolases: same reaction, different enzymes. Biochem. Soc. Trans. 18, 185-7
2. Fructose-bisphosphate aldolases: an evolutionary history. Trends Biochem. Sci. 17, 110-3
3. The complete amino acid sequence of human skeletal-muscle fructose-bisphosphate aldolase. Biochem. J. 249, 779-88
4. Human aldolase A natural mutants: relationship between flexibility of the C-terminal region and enzyme function. Biochem. J. 380, 51-6
5. The spectrum of aldolase B (ALDOB) mutations and the prevalence of hereditary fructose intolerance in Central Europe. Hum. Mutat. 25, 594