Figure 3: Crystal structure of the Ras/Raf inhibitor DARPin K55 binding to K-Ras G12V at 2.3 Å resolution.
From: Structural and functional characterization of a DARPin which inhibits Ras nucleotide exchange
DARPin K55 is shown binding to the active form of K-Ras G12V, crystallized in the presence of an uncleavable GTP analogue to ensure an active conformation. Two views of the complex are shown, rotated at 90° about a vertical axis, with switch 1 and 2 regions annotated (a). A comparison of the K-Ras/K55 complex with the KRas/RAF complex (PDB code: 3KUD) in b shows that the RAF and K55 binding sites overlap significantly and the switch1 loops of K-Ras in each complex are in essentially identical conformations.
