Fig. 3: Lipids induced rearrangement of dimerization interface.

a Overall structure of the SOS1^expand. Two monomers are colored in green and yellow, respectively. Lipid molecules are shown as red sticks and spheres. b–d Structural comparisons based on the whole dimeric structure between SOS1^expand and SOS1, illustrated using three slice views b–d as indicated by labeled panes; namely, TMD from extracellular side (b), TMD from intracellular side (c), and α-CTD from extracellular side (d). Black arrows indicated the helix movements of SOS1^expand compared to the SOS1. TM8 and TM9 are highlighted and labeled in b. e Structural comparison between the monomers of SOS1^expand and SOS1, using monomer itself as the alignment reference. TM8 and TM9 are labeled. f Four lipid molecules embedded at the dimer interface of SOS1. g, h Six lipid molecules embedded at the dimer interface of SOS1^expand. The extra lipid in a SOS1^expand monomer is highlighted in g, and its interactions with adjacent regions are shown in h. The flipped sidechain of Y270 was shown as sticks.