Slices through electron cryo-tomograms of lysed cells (a, b, g, h, and j) or purified membrane extensions (MEs) and membrane vesicles (MVs) (d and e) showing the presence of MVs and lysed membranes with a crown-like complex (red arrows and red boxed enlargements). Scale bars: 50 nm (a, b, h, and j), 100 nm (g), 10 nm (d and e). (c, f, and i) Central slices through subtomogram averages (with twofold symmetry along the Y-axis applied) of nine particles (c), four particles, (f), or three particles (i) of the crown-like complex in the indicated species. Scale bar is 20 nm. OL = outer leaflet, IL = inner leaflet.