Ribbon representations of KIT. (A) The crystal structure of an inactive conformation of KIT bound to imatinib (green) is shown.⁷  The activation loop, shown in the inactive state, is depicted in blue. The positions of D816 and N819 are shown as well as the hydrogen bond formed between these residues, which stabilizes the inactive conformation. (B) The active conformation of KIT is shown, with dasatinib (yellow) modeled into the active site. The activation loop (red) is depicted in the active conformation.