6Q9B
CI Membrane Arm focused refinement from Ovine respiratory SC I+III2
This is a non-PDB format compatible entry.
Summary for 6Q9B
| Entry DOI | 10.2210/pdb6q9b/pdb |
| EMDB information | 4479 |
| Descriptor | NADH:ubiquinone oxidoreductase core subunit S2,NADH:ubiquinone oxidoreductase core subunit S2, NADH:ubiquinone oxidoreductase subunit B5, Acyl carrier protein, ... (33 entities in total) |
| Functional Keywords | complex i, membrane arm, cellular respiration, mitochondria, electron transport |
| Biological source | Ovis aries (Sheep) More |
| Total number of polymer chains | 29 |
| Total formula weight | 614017.86 |
| Authors | Letts, J.A.,Sazanov, L.A. (deposition date: 2018-12-17, release date: 2019-08-21, Last modification date: 2024-11-20) |
| Primary citation | Letts, J.A.,Fiedorczuk, K.,Degliesposti, G.,Skehel, M.,Sazanov, L.A. Structures of Respiratory Supercomplex I+III2Reveal Functional and Conformational Crosstalk. Mol.Cell, 75:1131-1146.e6, 2019 Cited by PubMed Abstract: The mitochondrial electron transport chain complexes are organized into supercomplexes (SCs) of defined stoichiometry, which have been proposed to regulate electron flux via substrate channeling. We demonstrate that CoQ trapping in the isolated SC I+III limits complex (C)I turnover, arguing against channeling. The SC structure, resolved at up to 3.8 Å in four distinct states, suggests that CoQ oxidation may be rate limiting because of unequal access of CoQ to the active sites of CIII. CI shows a transition between "closed" and "open" conformations, accompanied by the striking rotation of a key transmembrane helix. Furthermore, the state of CI affects the conformational flexibility within CIII, demonstrating crosstalk between the enzymes. CoQ was identified at only three of the four binding sites in CIII, suggesting that interaction with CI disrupts CIII symmetry in a functionally relevant manner. Together, these observations indicate a more nuanced functional role for the SCs. PubMed: 31492636DOI: 10.1016/j.molcel.2019.07.022 PDB entries with the same primary citation |
| Experimental method | ELECTRON MICROSCOPY (3.9 Å) |
Structure validation
Download full validation report
