Abstract
Mitochondria are central to the efficient provision of energy for eukaryotic cells. The oxidative-phosphorylation system of mitochondria consists of a series of five major membrane complexes: NADH–ubiquinone oxidoreductase (commonly known as complex I), succinate–ubiquinone oxidoreductase (complex II), ubiquinol–cytochrome c oxidoreductase (cytochrome bc1 complex or complex III), cytochrome c–O2 oxidoreductase (complex IV), and F1F0–ATP synthase (complex V). Several lines of evidence have recently suggested that complexes I and III–V might interact to form supercomplexes. However, because of their fragility, the structures of these supercomplexes are still unknown. A stable supercomplex consisting of complex I and dimeric complex III was purified from plant mitochondria. Structural characterization by single-particle EM indicates a specific type of interaction between monomeric complex I and dimeric complex III in a 1:1 ratio. We present a model for how complexes I and III are spatially organized within the I+III2 supercomplex.
Original language | English |
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Pages (from-to) | 3225-3229 |
Journal | Proceedings of the National Academy of Sciences of the United States of America |
Volume | 102 |
Issue number | 9 |
DOIs | |
Publication status | Published - 2005 |