C, Cryo-EM map of the fully assembled ColE9 translocon, with local resolution range 4.5-16 Å. Component proteins are coloured as in panel b. The structure shows extracellular ColE9 creating a protein bridge between the two OMPs, BtuB and OmpF. The β-barrel of BtuB is tilted 35° relative to that of OmpF. TolB is located on the periplasmic side of OmpF, with no associations to BtuB. ColE9 and TolB regions of the map have weaker density than those of the β-barrels. 