Docking of ATP-analogs (ball and stick structures) into the active site of CK2 kinase (green, pdb:1DAW). The crosslinkers of ATP–ArN3 (A), ATP–BP (B), and ATP–DAz (C) protrude from the active site, but within close proximity to R47, G48, S51, K158, H160, and D175 (red). Images with the full kinase structure are shown in Figure S14. Video images are also available as Supplementary documents.