. . . . "Catalytic subunit of the tagatose-1,6-bisphosphate aldolase GatYZ, which catalyzes the reversible aldol condensation of dihydroxyacetone phosphate (DHAP or glycerone-phosphate) with glyceraldehyde 3-phosphate (G3P) to produce tagatose 1,6-bisphosphate (TBP). Requires GatZ subunit for full activity and stability. Is involved in the catabolism of galactitol (By similarity)." .