title: Evidence for a cytochrome f-Rieske protein subcomplex in the cytochrome b6f system from spinach chloroplasts.
abstract: The cytochrome b6f complex of spinach chloroplasts was prepared with minor modification according to the method of E. Hurt and G. Hauska (1981) Eur. J. Biochem. 117, 591-599) replacing, however, the final ultracentrifugation step by hydroxyapatite chromatography as suggested by M. F. Doyle and C.-A Yu (1985) Biochem. Biophys. Res. Commun. 131, 700-706). The purified complex was partially dissociated by treatment with 4 M urea or 0.1% sodium dodecyl sulfate (SDS) in the absence of reducing agents. A binary subcomplex consisting of cytochrome f and the Rieske iron-sulfur protein was observed under these conditions by three different methods: (a) hydroxyapatite chromatography; (b) extraction with an isopropanol/water/trifluoroacetic acid mixture; and (c) gel filtration in the presence of low SDS concentrations. The subcomplex dissociated into its components by treatment with mercaptoethanol. These results suggest a close interaction of the cytochrome f with the Rieske protein involving SH groups which under reducing conditions leads to complete dissociation of the subcomplex.
authors.affiliation: Technical University Berlin, Institute of Biochemistry and Molecular Biology, West Germany.
authors.forename: M
authors.initials: M
authors.lastname: el-Demerdash
authors.forename: J
authors.initials: J
authors.lastname: Salnikow
authors.forename: J
authors.initials: J
authors.lastname: Vater
mesh_terms: D002734:Chlorophyll / Q000378:metabolism; D002736:Chloroplasts / Q000201:enzymology* / Q000378:metabolism; D003573:Cytochrome b Group / Q000302:isolation & purification* / Q000378:metabolism; D045346:Cytochrome b6f Complex; D003580:Cytochromes / Q000302:isolation & purification* / Q000378:metabolism; D045348:Cytochromes f; D014450:Electron Transport Complex III; D007506:Iron-Sulfur Proteins / Q000302:isolation & purification* / Q000378:metabolism; D045342:Light-Harvesting Protein Complexes; D008623:Mercaptoethanol / Q000494:pharmacology; D008667:Metalloproteins / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D045322:Photosynthetic Reaction Center Complex Proteins; D010940:Plant Proteins / Q000378:metabolism; D014674:Plant Proteins, Dietary / Q000302:isolation & purification* / Q000378:metabolism
chemical_list: D003573:Cytochrome b Group; D003580:Cytochromes; D007506:Iron-Sulfur Proteins; D045342:Light-Harvesting Protein Complexes; D008667:Metalloproteins; D045322:Photosynthetic Reaction Center Complex Proteins; D010940:Plant Proteins; D014674:Plant Proteins, Dietary; C037989:Rieske iron-sulfur protein; D002734:Chlorophyll; D008623:Mercaptoethanol; D045346:Cytochrome b6f Complex; D045348:Cytochromes f; D014450:Electron Transport Complex III