Fig. 2.

Tandem MS of a subcomplex from T. thermophilus ATPase (ICL₁₂E₂G₂F) leads to disruption of the L₁₂ ring, releasing proteolipids L ± PE (red/green circle, 8,539 Da; red circles, 7,849 Da) and a stripped-complex ICE₂G₂F (blue squares, 184,242 Da). Atomic structure of the K₁₀ ring of E. hirae ATPase (50) with docking of 10 cardiolipins to show reduction in the inner diameter (A) and after docking subunit C (B). Models for sixfold symmetry of the L₁₂ ring with six PE molecules (green) (C) and with subunit C (blue) (51) docked into the ring (D). (Lower) Schematics of the rotor ring with 12-L subunits each having two transmembrane helices (red cylinders) and one conserved glu-63 (yellow) as seen in electron microscopy of 2D crystals (52) (i). Transformation into a sixfold symmetric ring (ii and iii). (iv) Comparison of the sixfold symmetrical model with electron microscopy data reported previously for the T. thermophilus ATPase (iv) (53).