ATP + D-fructose = ADP + D-fructose 6-phosphate + H(+) Inhibition by zinc ions (Potential). Inactivated by EDTA. Optimum pH is 7.0-8.0. Homodimer. Two isoforms, fructokinase I and II, have been found in this organism. Belongs to the ROK (NagC/XylR) family.