beta-D-fructose 1,6-bisphosphate + H2O = beta-D-fructose 6-phosphate + phosphate Binds 2 magnesium ions per subunit. Fructose-1,6-bisphosphatase II is not light-activated. Carbohydrate biosynthesis; gluconeogenesis. Homotetramer. There are two genes for FBPase in R.sphaeroides. Belongs to the FBPase class 1 family.