Three molecules of ubiquinone bind specifically to mitochondrial cytochrome bc1 complex

被引:51
作者
Bartoschek, S
Johansson, M
Geierstanger, BH
Okun, JG
Lancaster, CRD
Humpfer, E
Yu, L
Yu, CA [1 ]
Griesinger, C
Brandt, U
机构
[1] Oklahoma State Univ, Dept Biochem & Mol Biol, Stillwater, OK 74078 USA
[2] Goethe Univ Frankfurt, Inst Organ Chem, D-60439 Frankfurt, Germany
[3] Max Planck Inst Biophys Chem, D-37077 Gottingen, Germany
[4] Univ Frankfurt Klinikum, Inst Biochem 1, D-60590 Frankfurt, Germany
[5] Max Planck Inst Biophys, Abt Mol Membranbiol, D-60528 Frankfurt, Germany
[6] Bruker Analyt GMBH, D-76287 Rheinstetten, Germany
关键词
D O I
10.1074/jbc.C100365200
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Bifurcated electron flow to high potential "Rieske" iron-sulfur cluster and low potential heme b(L) is crucial for respiratory energy conservation by the cytochrome bc(1) complex. The chemistry of ubiquinol oxidation has to ensure the thermodynamically unfavorable electron transfer to heme b(L). To resolve a central controversy about the number of ubiquinol molecules involved in this reaction, we used high resolution magic-angle-spinning nuclear magnetic resonance experiments to show that two out of three n-decyl-ubiquinones bind at the ubiquinol oxidation center of the complex. This substantiates a proposed mechanism in which a charge transfer between a ubiquinol/ubiquinone pair explains the bifurcation of electron flow.
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页码:35231 / 35234
页数:4
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