May take part in developmental stage-specific or tissue -specific sugar-phosphate metabolisms. Protein acts on two substrates fructose 1,6-bisphosphate and fructose 1-phosphate (like other class I aldolases). beta-D-fructose 1,6-bisphosphate = D-glyceraldehyde 3-phosphate + dihydroxyacetone phosphate Optimum pH is 7.2-7.8 for isozyme alpha, and 7.2-7.5 for isozymes beta and gamma. Thermostability of the isozymes, calculated as the temperature causing half maximal stability, is 42-43 degrees Celsius for isozymes alpha and beta and 45 degrees Celsius for isozyme gamma. Carbohydrate degradation; glycolysis; D-glyceraldehyde 3-phosphate and glycerone phosphate from D-glucose: step 4/4. Homotetramer. Two additional mRNAs also exist (Alpha-beta and Beta-gamma). The translation product of Alpha-beta mRNA is isoform Alpha. Isozyme gamma is mainly expressed in the heads and partly in the thoraxes of adult flies. Isozyme alpha is expressed in all adult tissues. Isozyme beta is mainly expressed in adult abdominal regions and is also expressed in lesser amounts in other parts of the body and in earlier developmental stages. Isozyme alpha-beta shows strong expression in the abdomens of adults. Isozyme beta-gamma is expressed in adult heads. Isozyme gamma is first detected during late embryogenesis, is present through larval stages, declines in abundance during pupal stages and is maximum at eclosion. Isozyme beta is abundant during the earliest stages of embryogenesis, declines in amount and increases prior to hatching. Isozyme alpha is found only during the adult stage. Expression correlates to dietary behavior: high dietary activity in the larvae and adults causes active glycolysis and high expression levels. Isozyme alpha-beta is detected in the pupae and adults and isozyme beta-gamma in the adult. Belongs to the class I fructose-bisphosphate aldolase family.