1. Structure and Mechanism of Respiratory III–IV Supercomplexes in Bioenergetic Membranes
- Author
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Peter Brzezinski, Pia Ädelroth, and Agnes Moe
- Subjects
chemistry.chemical_classification ,biology ,Cytochrome ,010405 organic chemistry ,Cytochrome bc1 ,Cell Membrane ,Respiratory chain ,Review ,Saccharomyces cerevisiae ,General Chemistry ,Electron acceptor ,010402 general chemistry ,01 natural sciences ,0104 chemical sciences ,Electron Transport ,Electron Transport Complex IV ,Electron Transport Complex III ,Electron transfer ,chemistry ,Coenzyme Q – cytochrome c reductase ,Biophysics ,biology.protein ,Cytochrome c oxidase ,Protons ,Electrochemical gradient - Abstract
In the final steps of energy conservation in aerobic organisms, free energy from electron transfer through the respiratory chain is transduced into a proton electrochemical gradient across a membrane. In mitochondria and many bacteria, reduction of the dioxygen electron acceptor is catalyzed by cytochrome c oxidase (complex IV), which receives electrons from cytochrome bc1 (complex III), via membrane-bound or water-soluble cytochrome c. These complexes function independently, but in many organisms they associate to form supercomplexes. Here, we review the structural features and the functional significance of the nonobligate III2IV1/2Saccharomyces cerevisiae mitochondrial supercomplex as well as the obligate III2IV2 supercomplex from actinobacteria. The analysis is centered around the Q-cycle of complex III, proton uptake by CytcO, as well as mechanistic and structural solutions to the electronic link between complexes III and IV.
- Published
- 2021
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