Figure 8.

Variation in active site residues among sugar phosphate cyclases. Schematic drawing of residues lining the substrate-binding pocket in the DHQS·CBP complex shown in roughly the same orientation as in Figure 6. Each DHQS residue shown is labeled (cyan), and under that label are listed the corresponding residues found in the structures of DOIS (pink) and EEVS (purple) or, on the basis of the alignment in Figure 4, residues expected to be equivalent in DDGS and EVS (black). The CBP ligand is shown in bold. H-Bond interactions (dashed lines) and coordination bonds with Zn²⁺ (solid lines) are shown. The residue numbering corresponds to the representative proteins used in Figure 4 (AnDHQS, BcDOIS, ValA, AvDDGS, and AmEVS).