Fig. 9. Mechanism of the WT-KRAS catalyzed intrinsic GTP-hydrolysis in the presence of Tyr32. (A) The QM region (Lys16, Ser17, Tyr32, Thr35, Gln61, Lys117, Mg2+-ion, GTP and 4 water molecules) shown is explicitly in the reactant state (r(Owat-catlaytic–Pγ-phosphate) = 3.4 Å). The catalytic water is shown in cyan and the assisting water in orange. (B) Further characteristic points of the scan are: r = 2.06 Å (left), r = 2.04 Å (middle) and r = 1.6 Å (right). (C) Calculated energies along the reaction profile (points corresponding to stages shown in (A) and (B) are circled in red).
