Comparison of barrel and lipid densities of different prepore states. (A–E) Prepore states IV-Ia and pore state at different thresholds (A—prepore Ib; B—prepore II; C—prepore III; D—prepore IV; E—pore). Seven protomers are colored in different colors, and the lipid densities near the stem region at a lower threshold are shown in gray. The threshold values are mentioned at the bottom of the maps. The extra TM region of the prepore state III is shown using a black arrow.