Δfcj1 mitochondria contain zipperlike structures typical of oligomers of the F₁F_O–ATP synthase. Cryo-EM tomograms of isolated mitochondria. (A) Slice through a tomogram of a vitrified wild-type mitochondrion. (B) A CJ magnified (left) and surface rendered (right) corresponding to the boxed area in A is shown. Panels A and B are reprinted from Zick et al. (2009) with permission from Biochimica et Biophysica Acta. (C–G) Δfcj1 mitochondria. (C) Slice through a tomogram of a vitrified Δfcj1 mitochondrion. (D) Magnified view of boxed area in C (left) and surface-rendered representation (right) showing a zipperlike, regular arrangement with characteristics of the F₁ parts of F₁F_O–ATP synthase. The IM is shown in yellow, and F₁F_O–ATP synthases are shown in red. (E) A 10-nm thick slice of a tomogram cutting through particles typical of the F₁ parts of F₁F_O–ATP synthase in side views (arrow) and top views (boxed area). (F and G) Sections through the tomogram and volume-rendered top views of putative F₁F_O–ATP synthases arranged in double-row hexagonal stripes (F) and double-row square stripes (G) are shown. Bars: (A–C and E) 100 nm; (D, F, and G) 50 nm.