Figure 6.

(a) Constructed 2D-FEL of KRasGDP·Mg²⁺ from REMD simulations at 278 K; the reaction coordinates are identical to those in Figures 1, 3 and 4. The two substates are denoted as KRasGDP·Mg²⁺_S1.1 and KRasGDP·Mg²⁺_S1.2, respectively. The purple and black dots denote the projections of KRas in GEF·KRas (PDB: 6EPL) and the representative structure from KRas^GEFGDP·Mg²⁺ simulations. The units of RMSD and R_g are in Å and the free energy is in kcal/mol. (b) The cartoon representation of the overlapped secondary structures of KRasGDP·Mg²⁺_S1.1, KRasGDP·Mg²⁺_S1.2, KRas^GEF·GDP·Mg²⁺ and KRas of GEF·KRas. The loop of KRasGDP·Mg²⁺_S1.1 obstructs the insertion of the α-helix of GEF.