Extended Data Fig. 7: Lipid bilayer structure from CG-MD simulations with wild type CHMP1B-IST1 and lipid composition 17 simulations.

(a) Average outer leaflet headgroup patterning represented as a two-dimensional (θ, z) density from three independent replicates. (b) Representative snapshot of the outer tubule surface, with protein and solvent hidden (see Extended Data Fig. 2 for color coding). The scale and persistence of the hydrophobic defect appear similar to the WT simulations using Composition 1 (Fig. 1h). (c, d) Full radial density (c) and tail angle data (d) at the phenylalanine contact site (left panels) and the gap between the contact site (right panels). Radial density profiles correspond to different segments of the lipid, color coded as shown on the CG representations at the left. See Extended Data Fig. 2 for color coding. Outer leaflet densities are drawn as solid lines; inner leaflet densities are drawn as dashed lines. Note y-axis scale varies by lipid type due to abundance. Main structural features seen in the WT protein + lipid composition 1 simulations (Extended Data Fig. 2a, b) are preserved despite the varied composition. Tail angle distributions (d) behave similarly as well. Color scheme and line styles follow the same scheme as (c), and all distributions are normalized to 1. (e) Bilayer and leaflet thicknesses determined from mean radial lipid positions. Bilayer and leaflet thicknesses are summarized in the center table, and mean locations of midplane and glycerol planes are in the right table. The leaflets similarly show differential thinning, and the bilayer is only marginally thicker than that of the WT composition 1 simulations (Extended Data Fig. 2c), perhaps indicating that the reduction in overall SDPC content for composition 17 produces a less flexible, thicker membrane. (f) Local compositions per leaflet per zone, plotted as the axial z position of the zone to correspond with Fig. 3f (main text). See Fig. S3 for zone definitions. Error bars represent ± 1 standard deviation between replicates. Data for graphs in a, c–e, f are available as source data.

Source data