Characterization of DorC from Rhodobacter capsulatus, a c-type Cytochrome Involved in Electron Transfer to Dimethyl Sulfoxide Reductase
| Autor: | Anthony L. Shaw, Alejandro Hochkoeppler, Patrizia Bonora, Alastair G. McEwan, Graeme R. Hanson, Davide Zannoni |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
Iron-Sulfur Proteins
Ubiquinol Cytochrome Stereochemistry Ion chromatography Cytochrome c Group Photochemistry Biochemistry Rhodobacter capsulatus Electron Transport Electron transfer chemistry.chemical_compound Ferricyanides Molecular Biology Heme Rhodobacter biology Dimethyl sulfoxide Dithionite Cell Biology biology.organism_classification Molecular Weight Heme C chemistry Potentiometry biology.protein Electrophoresis Polyacrylamide Gel Oxidoreductases Oxidation-Reduction |
| Zdroj: | Journal of Biological Chemistry. 274:9911-9914 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.274.15.9911 |
| Popis: | The dorC gene of the dimethyl sulfoxide respiratory (dor) operon of Rhodobacter capsulatus encodes a pentaheme c-type cytochrome that is involved in electron transfer from ubiquinol to periplasmic dimethyl sulfoxide reductase. DorC was expressed as a C-terminal fusion to an 8-amino acid FLAG epitope and was purified from detergent-solubilized membranes by ion exchange chromatography and immunoaffinity chromatography. The DorC protein had a subunit Mr = 46,000, and pyridine hemochrome analysis indicated that it contained 5 mol heme c/mol DorC polypeptide, as predicted from the derived amino acid sequence of the dorC gene. The reduced form of DorC exhibited visible absorption maxima at 551.5 nm (alpha-band), 522 nm (beta-band), and 419 nm (Soret band). Redox potentiometry of the heme centers of DorC identified five components (n = 1) with midpoint potentials of -34, -128, -184, -185, and -276 mV. Despite the low redox potentials of the heme centers, DorC was reduced by duroquinol and was oxidized by dimethyl sulfoxide reductase. |
| Databáze: | OpenAIRE |
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