Letts 2016 Nature
Letts JA, Fiedorczuk K, Sazanov LA (2016) The architecture of respiratory supercomplexes. Nature 537:644-8. doi: 10.1038/nature19774 |
Letts JA, Fiedorczuk K, Sazanov Leonid A (2016) Nature
Abstract: Mitochondrial electron transport chain complexes are organized into supercomplexes responsible for carrying out cellular respiration. Here we present three architectures of mammalian (bovine) supercomplexes determined by cryo-electron microscopy. We identify two distinct arrangements of supercomplex CICIII2CIV (the respirasome)-a major 'tight' form and a minor 'loose' form (resolved at the resolution of 5.8 Γ and 6.7 Γ , respectively), which may represent different stages in supercomplex assembly or disassembly. We have also determined an architecture of supercomplex CICIII2 at 7.8 Γ resolution. All observed density can be attributed to the known 80 subunits of the individual complexes, including 132 transmembrane helices. The individual complexes form tight interactions that vary between the architectures, with complex IV subunit COX7a switching contact from complex III to complex I. The arrangement of active sites within the supercomplex may help control reactive oxygen species production. To our knowledge, these are the first complete architectures of the dominant, physiologically relevant state of the electron transport chain.
β’ Bioblast editor: Gnaiger E
Labels:
Stress:Oxidative stress;RONS Organism: Bovines
Enzyme: Complex I, Complex III, Complex IV;cytochrome c oxidase, Supercomplex