Figure 1.

Ligand-binding pocket of human CK2α in complex with eight bromobenzotriazole inhibitors. Protein–ligand contacts including hydrogen bonds are indicated in gray and halogen interactions in yellow. The side chains of most hinge region residues and the main chains of R47, K68, and D175 are omitted for clarity. Composite omit (gray, contoured at 1 rmsd) and F₀ – F_c (red/green contoured at ±3 rmsd) maps are shown for the ligand. The last two panels depict four poses observed for TBBt. With the exception of the compounds with 4,7-substitution, the bromobenzotriazoles can adopt a canonical pose. In many cases, particularly for the highly substituted benzotriazoles, multiple poses are observed.