The dimeric TMH region of Ire1 deforms the membrane. (A) Membrane deformation by the modeled, dimeric TMH region of Ire1. Water is shown in blue tones with a transparent surface representation. The phosphate moieties of POPC are shown as purple beads. (B) Configuration of a model TMH dimer obtained from atomistic molecular dynamics simulations. Protomers are shown as an orange ribbon, with the residues F544 and L549 highlighted in red. The phosphate moieties of POPC are shown as purple beads. The hydroxyl groups of cholesterol molecules are shown as red beads. Water is shown with a transparent surface representation. Right: Lipid and water are not shown for clarity. (C) The SEM of the thickness profile represented in Fig. 4 B. The thickness fluctuations in the proximity of the TMH dimer (not shown, centered in the middle of the box) give rise to a locally increased SEM of the thickness profile, but is much lower than the actual degree of membrane deformation as plotted in Fig. 4 B.