Figure 2.

Crystal structure of VR16-09 (panel A, PDB ID: 6G98) bound in the active site of human recombinant CA IX. The F_o − F_c omit map is contoured at 3σ. (Panel B) shows that VR16-09 fitted in apo-CA IX structure (PDB ID: 6FE2), demonstrating collision points with residues indicating too short inter-atomic distances if conformational changes had not occurred. Protein and ligand carbons are shown in green and black, respectively, and apo-CA IX residues are shown in light blue. Atom colors are: oxygen (red), nitrogen (blue), fluorine (light blue), and sulfur (yellow). (Panel C) shows comparison of binding modes for compounds VR16-09 (black carbons), VR16-10 (green carbons), VD12-09 (yellow carbons), and VD11-4-2 (light blue carbons). The zinc ion is shown as a gray sphere and residues participating in hydrogen bonds or charged interactions are also specified for the respective inhibitors. The figure was prepared using Pymol [61].