Figure 3.

Structural ensembles of the free state of Gab2_503-524 sampled by CS-restrained simulations. (A) Energy landscape of the WT sequence projected on two coordinates: the dihedral RMSD from the x-ray structure of the bound state and the gyration radius. The landscape is evaluated in discrete points using the Boltzmann equation and then interpolated using spline functions (see De Simone et al. (2,60) for additional details regarding the free-energy projections). The plot shows a basin composed of structures that are very similar to the bound state, corresponding to a low RMSD and a radius of gyration that is close to 8.5 Å (the value adopted in the bound structure). A bundle of conformations from the basin b2 is shown (backbone atoms only). Gray conformations are from the NMR ensemble (free state) and the red conformation corresponds to the crystal structure (bound state). (B) Based on this basin, we could estimate the population of bound conformations in the structural ensembles of the free state of the Gab2_503-524 sequences (WT and mutants) considered here. To see this figure in color, go online.