Electron transfer by domain movement in cytochrome bc1

@article{Zhang1998ElectronTB,
  title={Electron transfer by domain movement in cytochrome bc1},
  author={Zhaolei Zhang and Lisha Huang and V. M. Shulmeister and Young-In Chi and Kyeong Kyu Kim and Li-Wei Hung and Antony R. Crofts and Edward A Berry and Sung-Hou Kim},
  journal={Nature},
  year={1998},
  volume={392},
  pages={677-684}
}
The cytochrome bc1 is one of the three major respiratory enzyme complexes residing in the inner mitochondrial membrane. Cytochrome bc1 transfers electrons from ubiquinol to cytochrome c and uses the energy thus released to form an electrochemical gradient across the inner membrane. Our X-ray crystal structures of the complex from chicken, cow and rabbit in both the presence and absence of inhibitors of quinone oxidation, reveal two different locations for the extrinsic domain of one component… 
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References

SHOWING 1-10 OF 50 REFERENCES
Structure and function of the mitochondrial ubiquinol: cytochrome c reductase and NADH: ubiquinone reductase.
TLDR
The low-resolution three-dimensional structure of cytochrome reductase and of a bc, -subcomplex of the enzyme is determined by means of electron microscopy of membrane crystals.
Ubiquinone pair in the Qo site central to the primary energy conversion reactions of cytochrome bc1 complex.
TLDR
Measurement of the yield and rate of QH2 oxidation generated by single turnover flashes in the family of mutants suggests that the Qos and Qow domains serve different roles for the catalytic process, with the yield correlated linearly with Qos domain occupancy (QH2 or Q), suggesting that theQos domain exchanges Q or Qh2 with the Qpool at a rate which is much slower than the time scale of turnover.
Biological electron transfer
TLDR
New results from the photosynthetic reaction center protein confirm that the electronic-tunneling medium appears relatively homogeneous, with any variances evident having no impact on function, and that control of intraprotein rates and directional specificity rests on a combination of distance, free energy, and reorganization energy.
Crystal structure of the cytochrome bc1 complex from bovine heart mitochondria.
TLDR
The positions of the four iron centers within the bc1 complex and the binding sites of the two specific respiratory inhibitors antimycin A and myxothiazol were identified and the membrane-spanning region of each bc1complex monomer consists of 13 transmembrane helices, eight of which belong to cytochrome b.
Crystallization of mitochondrial ubiquinol-cytochrome c reductase.
TLDR
Ubiquinol-cytochrome c reductase of beef heart mitochondria was crystallized in the presence of decanoyl-N-methylglucamide, heptanetriol, and sodium chloride with poly(ethylene glycol) as precipitant to show full enzymatic activity when redissolved in aqueous solution.
Identification of the binding site on cytochrome c1 for cytochrome c.
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