Figure 1.

RAS/mitogen-activated protein kinase (MAPK) pathway signaling and protein–protein interactions. (A) Pathway signaling showing normal, RAS mutant, and BRAF V600E mutant signaling. (B) Structure of the Ras-like small GTPase Rap1A (white) with Switch I (yellow) and Switch II (magenta) bound to the RAS-binding domain (RBD) domain (green) of CRAF (Protein Data Bank [PDB] code 1C1Y). (C) Cartoon of two proposed RAS dimers proposed by Muratcioglu et al. (2015) formed either by the β2 strand from Switch I, which forms a dimer analogous to the Ras–RBD interactions, or by mediated α3/α4.