Timeline for the identification of key structures for each of the three respiratory chain complexes present in the supercomplex.
Structures solved using X-ray crystallography are coloured by yellow nodes, with Cryo-EM structures coloured by orange nodes. Structures which had low-quality density maps (PDB:1QCR and 5XTI) or only existing as an alpha-helical model (membrane region of PDB:3M9S) are depicted using the surface representation, whereas high-resolution structures are shown using the ribbon representation. Note: the CI2/CIII2/CIV2 megacomplex structure is a top view, whereas other structures are shown as side views.