Evidence for a cytochrome f-Rieske protein subcomplex in the cytochrome b6f system from spinach chloroplasts.
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.
el-Demerdash
M
M
Technical University Berlin, Institute of Biochemistry and Molecular Biology, West Germany.
Salnikow
J
J
Vater
J
J
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
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