Figure 9.

Extended network of interactions at the active site cleft. Binding of the consensus site peptide and ATP to the active site cleft creates a contiguous network of interactions that extend well beyond the direct site of phosphoryl transfer. The two arrows indicate regions that are influenced by nonconserved parts of the molecule. The left arrow highlights the position of Tyr-330 in the “tail.” The right arrow indicates the region that is influenced by the A-helix at the amino terminus. The γ-phosphate of ATP is yellow, the inhibitor peptide, PKI(18–22), is red, and the activation segment from Asp-184 in the DFG loop to Glu-208 is gray with β-strand 9 and the activation loop (residues 165–171) highlighted in white.