Fig. 3.

Crystal structures of KRAS WT (green) and G13D (cyan). (A) Superimposition of wild type KRAS and G13D. The conformations of switch I and II regions are almost identical. (B) Backbone interactions of G13D. The Asp13 main chain amide is 2.8 Å away from β-phosphate of GDP and carbonyl is 2.8 Å away from the amine of Lys117. (C) 2D scheme of Hydrogen bonding between β-phosphate of GDP and backbone of P-loop (residues 13–17) in WT (left) and G13D (right).