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Electron-Transfer Pathways in the Heme and Quinone-Binding Domain of Complex II (Succinate Dehydrogenase)

[Image: see text] Single electron transfers have been examined in complex II (succinate:ubiquinone oxidoreductase) by the method of pulse radiolysis. Electrons are introduced into the enzyme initially at the [3Fe–4S] and ubiquinone sites followed by intramolecular equilibration with the b heme of th...

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Autores principales: Anderson, Robert F., Shinde, Sujata S., Hille, Russ, Rothery, Richard A., Weiner, Joel H., Rajagukguk, Sany, Maklashina, Elena, Cecchini, Gary
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2014
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3985935/
https://www.ncbi.nlm.nih.gov/pubmed/24559074
http://dx.doi.org/10.1021/bi401630m
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author Anderson, Robert F.
Shinde, Sujata S.
Hille, Russ
Rothery, Richard A.
Weiner, Joel H.
Rajagukguk, Sany
Maklashina, Elena
Cecchini, Gary
author_facet Anderson, Robert F.
Shinde, Sujata S.
Hille, Russ
Rothery, Richard A.
Weiner, Joel H.
Rajagukguk, Sany
Maklashina, Elena
Cecchini, Gary
author_sort Anderson, Robert F.
collection PubMed
description [Image: see text] Single electron transfers have been examined in complex II (succinate:ubiquinone oxidoreductase) by the method of pulse radiolysis. Electrons are introduced into the enzyme initially at the [3Fe–4S] and ubiquinone sites followed by intramolecular equilibration with the b heme of the enzyme. To define thermodynamic and other controlling parameters for the pathways of electron transfer in complex II, site-directed variants were constructed and analyzed. Variants at SdhB-His207 and SdhB-Ile209 exhibit significantly perturbed electron transfer between the [3Fe–4S] cluster and ubiquinone. Analysis of the data using Marcus theory shows that the electronic coupling constants for wild-type and variant enzyme are all small, indicating that electron transfer occurs by diabatic tunneling. The presence of the ubiquinone is necessary for efficient electron transfer to the heme, which only slowly equilibrates with the [3Fe–4S] cluster in the absence of the quinone.
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spelling pubmed-39859352015-02-21 Electron-Transfer Pathways in the Heme and Quinone-Binding Domain of Complex II (Succinate Dehydrogenase) Anderson, Robert F. Shinde, Sujata S. Hille, Russ Rothery, Richard A. Weiner, Joel H. Rajagukguk, Sany Maklashina, Elena Cecchini, Gary Biochemistry [Image: see text] Single electron transfers have been examined in complex II (succinate:ubiquinone oxidoreductase) by the method of pulse radiolysis. Electrons are introduced into the enzyme initially at the [3Fe–4S] and ubiquinone sites followed by intramolecular equilibration with the b heme of the enzyme. To define thermodynamic and other controlling parameters for the pathways of electron transfer in complex II, site-directed variants were constructed and analyzed. Variants at SdhB-His207 and SdhB-Ile209 exhibit significantly perturbed electron transfer between the [3Fe–4S] cluster and ubiquinone. Analysis of the data using Marcus theory shows that the electronic coupling constants for wild-type and variant enzyme are all small, indicating that electron transfer occurs by diabatic tunneling. The presence of the ubiquinone is necessary for efficient electron transfer to the heme, which only slowly equilibrates with the [3Fe–4S] cluster in the absence of the quinone. American Chemical Society 2014-02-21 2014-03-18 /pmc/articles/PMC3985935/ /pubmed/24559074 http://dx.doi.org/10.1021/bi401630m Text en Copyright © 2014 American Chemical Society
spellingShingle Anderson, Robert F.
Shinde, Sujata S.
Hille, Russ
Rothery, Richard A.
Weiner, Joel H.
Rajagukguk, Sany
Maklashina, Elena
Cecchini, Gary
Electron-Transfer Pathways in the Heme and Quinone-Binding Domain of Complex II (Succinate Dehydrogenase)
title Electron-Transfer Pathways in the Heme and Quinone-Binding Domain of Complex II (Succinate Dehydrogenase)
title_full Electron-Transfer Pathways in the Heme and Quinone-Binding Domain of Complex II (Succinate Dehydrogenase)
title_fullStr Electron-Transfer Pathways in the Heme and Quinone-Binding Domain of Complex II (Succinate Dehydrogenase)
title_full_unstemmed Electron-Transfer Pathways in the Heme and Quinone-Binding Domain of Complex II (Succinate Dehydrogenase)
title_short Electron-Transfer Pathways in the Heme and Quinone-Binding Domain of Complex II (Succinate Dehydrogenase)
title_sort electron-transfer pathways in the heme and quinone-binding domain of complex ii (succinate dehydrogenase)
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3985935/
https://www.ncbi.nlm.nih.gov/pubmed/24559074
http://dx.doi.org/10.1021/bi401630m
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