Figure 3.

Class averages and 3D maps of FtsH dodecamers.A–D, class averages of the negatively stained specimen representing its typical side views. The scale bar represents 11 nm. E, schematic representation of the class averages highlighting with dashed lines six linking peptides present in the protein sequence. F, 3D maps and a cross section of different dodecameric conformations calculated from images of the negatively stained specimen. G, fitting of two cytosolic domains (PDB 4WW0) to the dodecamer map. H, cryo-EM class averages of the AaFtsH dodecameric specimen. Left to right: a hexamer side view, followed by four typical side views of a dodecamer. I, left to right: S-shaped FtsH dodecamers with variably intertwined N-terminal domains at resolutions of 17 Å (intertwined type), 19.5 Å (lamellar type), and 20.5 Å (touching type), respectively, and a V-shaped dodecamer at 12.3 Å.