Figure 4 - full size

Figure 4.
FIGURE 4. Structural changes occurring during the enzyme reaction. A, close-up view of loops A and B of the wild-type BiSP covalent intermediate (molecule A; cyan) superimposed on the glucose product-bound form (molecule B; yellow). The bound glucose of molecule B is shown for clarity. B, close-up view of loops A and B and the noncovalently bound glucose molecule of the wild-type BiSP-glucose complex. Glucose 1-phosphate (yellow) has been modeled based on the position of the glucose interacting with Arg^135 and Tyr^344. C, proposed intermolecular phosphate-binding site created by two Arg^135 residues. The distances indicated by dashed lines are 3.9 Å. The bound sucrose molecules are shown as red van der Waals spheres.