Fig. 2: The membrane arm with lipid and carotenoid molecules.

a Distribution of cofactors in NDH-Fd structure. Fe–S clusters are shown as spheres, PQ (orange), lipids (blue), and carotenoids (red) are shown as sticks. b Three lipid molecules (shown as ball-and-stick mode) contribute to the stabilization of NdhL, NdhA, NdhC, and NdhG. c The stromal side view of the lipid distribution at the distal part of the membrane arm. d Two carotenoid (BCR) and three lipid molecules participate in NdhF–NdhD interactions. e The binding pocket of BCR2. The color codes of subunits are the same as those in Fig. 1. The horizontal helix of NdhF is shown as blue cartoon. The BCR molecules are shown as red sticks. Lipid molecules are colored yellow for phosphatidyl glycerol (PG), gray for sulfoquinovosyldiacyl glycerol (SQDG), orange for monogalactosyldiacyl glycerol (MGDG), and blue for DGDG in b–e.