Figure 2.
Structure of K-Ras4BA146T. A, Comparison of K-Ras4BWT, K-Ras4BA146T, and K-Ras4BG12D X-ray structures demonstrating extension of switch 1 (yellow) and increased flexibility of switch 2 (highlighted in green) in K-Ras4BA146T. B, 2Fo-Fc electron density contoured at 1.4σ for X-ray crystal structure of GDP:K-Ras4BA146T. GDP is colored by element and surrounding active site residues are labeled. The active site Mg from superimposed structure of GDP:K-Ras4BWT (4OBE) is also shown in magenta, demonstrating no density in this location for K-Ras4BA146T. C, Regions of K-Ras4BA146T (highlighted in red) demonstrating increased deuterium exchange relative to WT, as measured by HDX-MS. D, SOS:H-Ras (PDB 1bkd) structure demonstrates the SOS-RAS binding interface. Multiple regions of H-Ras would be covered by switch 1 in the closed form.