New article - anticooperative dimer

Raul G. Covian, Thomas Kleinschroth, Bernd A. Ludwig, and Bernard L. Trumpower.
Asymmetric binding of stigmatellin to the dimeric Paracoccus denitrificans bc1 complex: Evidence for anti-cooperative ubiquinol oxidation and communication between center P ubiquinol oxidation sites. J. Biol. Chem. published 8 June 2007, 10.1074/jbc.M702132200

Recent article: Rieske proton ENDOR

Probing electronic and structural properties of the reduced [2Fe-2S] cluster by orientation-selective H-1 ENDOR spectroscopy: Adrenodoxin versus Rieske iron-sulfur protein
Kappl R, Ebelshauser M, Hannemann F, Bernhardt R, Huttermann J(2006) APPLIED MAGNETIC RESONANCE 30 (3-4): 427-459

New Article

Jonathan L. Cape, Michael K. Bowman, and David M. Kramer.
A semiquinone intermediate generated at the Qo site of the cytochrome bc1 complex: Importance for the Q-cycle and superoxide production.
PNAS. published 30 April 2007, 10.1073/pnas.0702621104

New Article:

Kessl JJ, Moskalev NV, Gribble GW, Nasr M, Meshnick SR, Trumpower BL.
Parameters determining the relative efficacy of hydroxy-naphthoquinone inhibitors of the cytochrome bc(1) complex.
Biochim Biophys Acta. 2007 Feb 27; [Epub ahead of print]
PMID: 17383607

Recent Article

Molecular Coevolution of the Vertebrate Cytochrome c1 and Rieske Iron Sulfur Protein in the Cytochrome bc1 Complex
Kimberly Baer, David A. McClellan http://www.biotconf.org/2006/3-Mcclellan-28.pdf

New Article

Jian Zhu, Tsuyoshi Egawa , Syun-Ru Yeh , Linda Yu, and Chang-An Yu. Simultaneous reduction of iron-sulfur protein and cytochrome bL during ubiquinol oxidation in cytochrome bc1 complex. Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0607812104

Recent Article

Lebrun E, Santini JM, Brugna M, Ducluzeau AL, Ouchane S, Schoepp-Cothenet B, Baymann F, Nitschke W. The Rieske protein: a case study on the pitfalls of multiple sequence alignments and phylogenetic reconstruction.
Mol Biol Evol. 2006 Jun;23(6):1180-91. Epub 2006 Mar 28.
PMID: 16569761

Recent Article

Zatsman AI, Zhang H, Gunderson WA, Cramer WA, Hendrich MP. Heme-heme interactions in the cytochrome b6f complex: EPR spectroscopy and correlation with structure.
J Am Chem Soc. 2006 Nov 8;128(44):14246-7. PMID: 17076484

For new questions, comments:

Only moderators can initiate new posts. Anyone can add a comment to an existing post, but the comment should be related. So this entry is for general questions or comments not related to any of the articles. Feel free to chime in!

Astrid R. Klingen, Hildur Palsdottir, Carola Hunte and G. Matthias Ullmann
Redox-linked protonation state changes in cytochrome bc1 identified by Poisson–Boltzmann electrostatics calculations
Biochimica et Biophysica Acta (BBA) - Bioenergetics
Article in Press, Uncorrected Proof - doi:10.1016/j.bbabio.2007.01.016

Wenz T, Covian R, Hellwig P, Macmillan F, Meunier B, Trumpower BL, Hunte C.
Mutational Analysis of Cytochrome b at the Ubiquinol Oxidation Site of Yeast Complex III.
J Biol Chem. 2007 Feb 9;282(6):3977-88. Epub 2006 Dec 4.
PMID: 17145759

A Comparison of Stigmatellin Conformations, Free and Bound to the Photosynthetic Reaction Center and the Cytochrome bc1 Complex
Journal of Molecular Biology, In Press, Accepted Manuscript, Available online 11 February 2007,
C. Roy D. Lancaster, Carola Hunte, Jack Kelley III, Bernard L. Trumpower and Robert Ditchfield
PDF (1029 K)

Rajagukguk S, Yang S, Yu CA, Yu L, Durham B, Millett F.
Effect of Mutations in the Cytochrome b ef Loop on the Electron-Transfer Reactions of the Rieske Iron-Sulfur Protein in the Cytochrome bc(1) Complex.
Biochemistry. 2007 Jan 25; [Epub ahead of print]
PMID: 17253777

Mulkidjanian AY.
Proton translocation by the cytochrome bc1 complexes of phototrophic bacteria: introducing the activated Q-cycle.
Photochem Photobiol Sci. 2007 Jan;6(1):19-34. Epub 2006 Dec 7.
PMID: 17200733

Bruscella P, Appia-Ayme C, Levican G, Ratouchniak J, Jedlicki E, Holmes DS, Bonnefoy V.
Differential expression of two bc1 complexes in the strict acidophilic chemolithoautotrophic bacterium Acidithiobacillus ferrooxidans suggests a model for their respective roles in iron or sulfur oxidation.
Microbiology. 2007 Jan;153(Pt 1):102-10.
PMID: 17185539

Zhang H, Osyczka A, Moser CC, Dutton PL.
Resilience of Rhodobacter sphaeroides cytochrome bc1 to heme c1 ligation changes.
Biochemistry. 2006 Dec 5;45(48):14247-55.
PMID: 17128964

Miki T, Umeda M, Harada Y.
J Biochem (Tokyo). 2007 Jan 18; [Epub ahead of print]
Inhibition of Reversed Electron Transfer and Proton Transport in the Beef Heart Cytochrome bc1 Complex by Chemical Modification.
PMID: 17234684

Kolling DJ, Brunzelle JS, Lhee S, Crofts AR, Nair SK.
Atomic Resolution Structures of Rieske Iron-Sulfur Protein:
Role of Hydrogen Bonds in Tuning the Redox Potential of Iron-Sulfur Clusters.
Structure. 2007 Jan;15(1):29-38.
doi:10.1016/j.str.2006.11.012

Extinction Coefficients?

What are the most accurate extinction coefficients for determining the concentration of the bc1 complex or its individual chromophores? Are there significant differences between species?
Not important for many purposes, but it is if you are looking at stoichiometry in supercomplexes, studying the shape of inhibitor titration curves, counting the quinones, or quibbling over who has the highest turnover number!

Baymann F, Giusti F, Picot D, Nitschke W.
The ci/bH moiety in the b6f complex studied by EPR: A pair of strongly interacting hemes.
Proc Natl Acad Sci U S A. 2007 Jan 3; [Epub ahead of print]
PMID: 17202266