The pharma-interface and pharma-motifs of the tyrosine-protein kinase KIT-Imatinib complex. (A) The four residues (E640, T670, C673 and D810) of KIT protein (cyan) form hydrogen bonds (green dashed lines) with Imatinib (magenta) and are conserved in this family. (B) The conserved residue K807 plays an important role to stabilize the kinase structures. (C) The conserved residues in these pharma-motifs are related to phosphorylation of KIT. Asterisks mark the residues interacting with the ATP with hydrogen bonds.