beta-D-fructose 1,6-bisphosphate + H2O = beta-D-fructose 6-phosphate + phosphate Binds 3 Mg(2+) ions per subunit. Subject to complex allosteric regulation. The enzyme can assume an active R-state, or an inactive T-state. Intermediate conformations may exist. AMP acts as allosteric inhibitor. AMP binding affects the turnover of bound substrate and not the affinity for substrate (By similarity). Carbohydrate biosynthesis; gluconeogenesis. Homotetramer. The Pro/N-degron targets the protein for proteasomal degradation when cells are shifted to glucose-containing growth medium. Ubiquitinated (PubMed:22645139). Targeted for proteasomal degradation when cells are shifted to glucose-containing growth medium (PubMed:12686616, PubMed:18508925, PubMed:22645139, PubMed:28126757). Present with 589 molecules/cell in log phase SD medium. Belongs to the FBPase class 1 family.