Fig. 8: Helical row model of type III ATP synthase extrapolated from the single-particle reconstruction.

Six copies of ATP synthase tetramer (colored densities) arranged by superposition according to the inherent architecture (using a bridging tetramer map, not shown) results in a row with right-handed helical twist. Two-fold propagation of the six ATP synthase tetramer copies (gray colored copies) completes a helical row with 36 ATP synthase dimers in one helical turn.