Fig. 6: Proposed model for SOS1 activation.
TM5 and TM6 helices from the core domains are illustrated and labeled. Side chains of the D201TM6 are shown as sticks. Intracellular domains including the HCs, CNBLD, and β-CTD are represented according to their structure and labeled. The C-loops and C-helices are shown as tubes. The unresolved structure of the C-terminal tail is shown in dashed lines. a The inhibited state is shown where the intracellular domains are tightly packed together. The TM5b occludes D201TM6 and makes it inaccessible from the intracellular side. b The active state is demonstrated, where the intracellular domains are unpacked following the release of the C-loop and C-helices. The phosphorylated region is denoted by a red dotted circle. The core ___domain undergoes elevator-like movement between the inward-facing conformation and outward-facing conformation, depicted using opaque and transparent cartoons, respectively. Arrows indicate the movement of the core ___domain from the inward-facing state to the outward-facing state.
