FIGURE 9.

Accessory subunit NDUFA10. (A) The structure of CI (PDB: 6ZKC) in cartoon with the surface of NDUFA10 (cadet blue) shown, the core subunits colored as in Figure 1A and the accessory subunits grey. (B) Transparent surface and cartoon of O. aries NDUFA10 (PDB: 6ZKC). The P-loop (pink), DR (Y/H) motif (red), lid region (orange) and base sensing loop (yellow) are shown as thickened cartoon. (C) Cartoon of NDUFA10 with the density map (grey) from M. musculus CI bound to the Q-site inhibitor piericidin (PDB: 7B93). Mg²⁺ ATP and key binding residues are shown as sticks and colored by element. (D) Cartoon of NDUFA10 colored by atomic displacement parameter (ADP) in CI (PDB: 6ZKO). Red: most flexible, Blue: least flexible. (E,F) State dependent interactions between NDUFA5 and NDUFA10 involve the base-sensing loop. (E) Transparent surface of closed A-state CI showing NDUFA10 and NDUFA5 (auburn) as cartoons (PDB: 6ZKC). (F) Transparent surface of open D-state CI showing NDUFA10 and NDUFA5 as cartoons (PDB: 6ZKD). Key residues involved in the interaction are shown as sticks and colored by element. NDUFA10: cadet blue, NDUFA5: auburn.