The type III secretion (T3S) injectisome is critical for the pathogenicity of many Gram-negative bacteria.

This 3.5-MDa macromolecular assembly spans both bacterial membranes and that of the infected host cell.

Here the regions that span the inner membrane (15-fold symmetrical, beta strands) and outer membranes (24-fold symmetrical, helices) of the bacterium are shown.)


Near-atomic-resolution cryo-EM analysis of the Salmonella T3S injectisome basal body
Worrall LJ, Hong C, Vuckovic M, Deng W, Bergeron JR, Majewski DD, Huang RK, Spreter T, Finlay BB, Yu Z, Strynadka NC,
(2016) Nature 540: 597-601
(PubMed)

5tcr(PDB)