InterPro domain: IPR000771

Class-II aldolases [ 1 ], mainly found in prokaryotes and fungi, are homodimeric enzymes, which require a divalent metal ion, generally zinc, for their activity. They include fructose-bisphosphate aldolase [ 2 , 3 ], a glycolytic enzyme that catalyses the reversible aldol cleavage or condensation of fructose-1,6-bisphosphate into dihydroxyacetone-phosphate and glyceraldehyde 3-phosphate. The family also includes the Escherichia coli galactitol operon protein, gatY, which catalyses the transformation of tagatose 1,6-bisphosphate into glycerone phosphate and D-glyceraldehyde 3-phosphate; and E. coli N-acetyl galactosamine operon protein, agaY, which catalyses the same reaction. There are two histidine residues in the first half of the sequence of these enzymes that have been shown to be involved in binding a zinc ion [ 3 ].

1. Fructose-bisphosphate aldolases: an evolutionary history. Trends Biochem. Sci. 17, 110-3
2. The fructose-1,6-bisphosphate aldolases: same reaction, different enzymes. Biochem. Soc. Trans. 18, 185-7
3. Identification of zinc-binding ligands in the class II fructose-1,6-bisphosphate aldolase of Escherichia coli. FEBS Lett. 318, 11-6