For soaking experiments, incisions were made into the Laminex cover over base wells containing crystals. 10 ul of mother liquor containing 1 mM of either Compound 7 or 9 were added to the well, this was then re-sealed using Crystal Clear Sealing Tape (Hampton Research). Crystals were incubated for 1 hour with a final ligand concentration of 925 μM. Single crystals were mounted in LithoLoops (Molecular Dimensions Ltd) and flash-frozen in liquid nitrogen without the addition of further cryoprotectant.