This Jmol image shows E.coli PFK-1 bound to either AMP, ADP, or ATP (AXP) and to phosphorylated fructose (either F-6-P or F-1-6-P, FXP). Although the displayed protein is a homodimer, only one set of bound ligands is shown.

  • Click on the "AXP Highlight" to turn on/off a yellow surface on the AXP residue(s).
  • Click on the "FXP Highlight" box to turn on/off a green surface on the FXP residue.


  1. Which AXP (AXP-1 or AXP-2) is bound in the active site? Which is found in the allosteric site?
  2. Does this structure show the enzyme complexed with reactants or products? Justify your answer with reference to the structure.
  3. Does this structure reflect the activated (R) or inhibited (T) form of PFK-1? Briefly justify your answer.