Direct assignment of EPR spectra to structurally defined iron-sulfur clusters in complex I by double electron-electron resonance
In oxidative phosphorylation, complex I (NADH:quinone oxidoreductase) couples electron transfer to proton translocation across an energy-transducing membrane. Complex I contains a flavin mononucleotide to oxidize NADH, and an unusually long series of iron-sulfur (FeS) clusters, in several subunits,...
| Үндсэн зохиолчид: | , , , , , |
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| Формат: | Journal article |
| Хэл сонгох: | English |
| Хэвлэсэн: |
National Academy of Sciences
2010
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| Нөхцлүүд: |
| _version_ | 1826268862996283392 |
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| author | Roessler, M King, M Robinson, A Armstrong, F Harmer, J Hirst, J |
| author_facet | Roessler, M King, M Robinson, A Armstrong, F Harmer, J Hirst, J |
| author_sort | Roessler, M |
| collection | OXFORD |
| description | In oxidative phosphorylation, complex I (NADH:quinone oxidoreductase) couples electron transfer to proton translocation across an energy-transducing membrane. Complex I contains a flavin mononucleotide to oxidize NADH, and an unusually long series of iron-sulfur (FeS) clusters, in several subunits, to transfer the electrons to quinone. Understanding coupled electron transfer in complex I requires a detailed knowledge of the properties of individual clusters and of the cluster ensemble, and so it requires the correlation of spectroscopic and structural data: This has proved a challenging task. EPR studies on complex I from Bos taurus have established that EPR signals N1b, N2 and N3 arise, respectively, from the 2Fe cluster in the 75 kDa subunit, and from 4Fe clusters in the PSST and 51 kDa subunits (positions 2, 7, and 1 along the seven-cluster chain extending from the flavin). The other clusters have either evaded detection or definitive signal assignments have not been established. Here, we combine double electron-electron resonance (DEEP) spectroscopy on B. taurus complex I with the structure of the hydrophilic domain of Thermus thermophilus complex I. By considering the magnetic moments of the clusters and the orientation selectivity of the DEER experiment explicitly, signal N4 is assigned to the first 4Fe cluster in the TYKY subunit (position 5), and N5 to the all-cysteine ligated 4Fe cluster in the 75 kDa subunit (position 3). The implications of our assignment for the mechanisms of electron transfer and energy transduction by complex I are discussed. |
| first_indexed | 2024-03-06T21:16:06Z |
| format | Journal article |
| id | oxford-uuid:3fd6173a-4155-446d-b371-daf5a3f2f966 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-06T21:16:06Z |
| publishDate | 2010 |
| publisher | National Academy of Sciences |
| record_format | dspace |
| spelling | oxford-uuid:3fd6173a-4155-446d-b371-daf5a3f2f9662022-03-26T14:34:28ZDirect assignment of EPR spectra to structurally defined iron-sulfur clusters in complex I by double electron-electron resonanceJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:3fd6173a-4155-446d-b371-daf5a3f2f966Inorganic chemistryChemistry & allied sciencesEnglishOxford University Research Archive - ValetNational Academy of Sciences2010Roessler, MKing, MRobinson, AArmstrong, FHarmer, JHirst, JIn oxidative phosphorylation, complex I (NADH:quinone oxidoreductase) couples electron transfer to proton translocation across an energy-transducing membrane. Complex I contains a flavin mononucleotide to oxidize NADH, and an unusually long series of iron-sulfur (FeS) clusters, in several subunits, to transfer the electrons to quinone. Understanding coupled electron transfer in complex I requires a detailed knowledge of the properties of individual clusters and of the cluster ensemble, and so it requires the correlation of spectroscopic and structural data: This has proved a challenging task. EPR studies on complex I from Bos taurus have established that EPR signals N1b, N2 and N3 arise, respectively, from the 2Fe cluster in the 75 kDa subunit, and from 4Fe clusters in the PSST and 51 kDa subunits (positions 2, 7, and 1 along the seven-cluster chain extending from the flavin). The other clusters have either evaded detection or definitive signal assignments have not been established. Here, we combine double electron-electron resonance (DEEP) spectroscopy on B. taurus complex I with the structure of the hydrophilic domain of Thermus thermophilus complex I. By considering the magnetic moments of the clusters and the orientation selectivity of the DEER experiment explicitly, signal N4 is assigned to the first 4Fe cluster in the TYKY subunit (position 5), and N5 to the all-cysteine ligated 4Fe cluster in the 75 kDa subunit (position 3). The implications of our assignment for the mechanisms of electron transfer and energy transduction by complex I are discussed. |
| spellingShingle | Inorganic chemistry Chemistry & allied sciences Roessler, M King, M Robinson, A Armstrong, F Harmer, J Hirst, J Direct assignment of EPR spectra to structurally defined iron-sulfur clusters in complex I by double electron-electron resonance |
| title | Direct assignment of EPR spectra to structurally defined iron-sulfur clusters in complex I by double electron-electron resonance |
| title_full | Direct assignment of EPR spectra to structurally defined iron-sulfur clusters in complex I by double electron-electron resonance |
| title_fullStr | Direct assignment of EPR spectra to structurally defined iron-sulfur clusters in complex I by double electron-electron resonance |
| title_full_unstemmed | Direct assignment of EPR spectra to structurally defined iron-sulfur clusters in complex I by double electron-electron resonance |
| title_short | Direct assignment of EPR spectra to structurally defined iron-sulfur clusters in complex I by double electron-electron resonance |
| title_sort | direct assignment of epr spectra to structurally defined iron sulfur clusters in complex i by double electron electron resonance |
| topic | Inorganic chemistry Chemistry & allied sciences |
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