title: The membrane-extrinsic domain of cytochrome b(558/566) from the archaeon Sulfolobus acidocaldarius performs pivoting movements with respect to the membrane surface.
abstract: The orientation of the membrane-attached cytochrome b(558/566)-haem with respect to the membrane was determined by electron paramagnetic resonance spectroscopy on two-dimensionally ordered oxidised membrane fragments from Sulfolobus acidocaldarius. Unlike the other redox centres in the membrane, the cytochrome b(558/566)-haem was found to cover a range of orientations between 25 degrees and 90 degrees. The described results are reminiscent of those obtained on the Rieske cluster of bc complexes and indicate that the membrane-extrinsic domain of cytochrome b(558/566) can perform pivoting motion between two extreme positions. Such a conformational flexibility is likely to play a role in electron transfer with its redox partners.
authors.affiliation: Laboratoire de Bioenérgétique et Ingénierie des Protéines, CNRS, UPR 9036, Institut de Biologie Structurale et Microbiologie, Marseille, France. schoepp@ibsm.cnrs-mrs.fr
authors.forename: B
authors.initials: B
authors.lastname: Schoepp-Cothenet
authors.forename: M
authors.initials: M
authors.lastname: Schütz
authors.forename: F
authors.initials: F
authors.lastname: Baymann
authors.forename: M
authors.initials: M
authors.lastname: Brugna
authors.forename: W
authors.initials: W
authors.lastname: Nitschke
authors.forename: H
authors.initials: H
authors.lastname: Myllykallio
authors.forename: C
authors.initials: C
authors.lastname: Schmidt
mesh_terms: D000595:Amino Acid Sequence; D002462:Cell Membrane / Q000737:chemistry; D003573:Cytochrome b Group / Q000737:chemistry* / Q000235:genetics; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D008969:Molecular Sequence Data; D019255:NADPH Oxidases; D010084:Oxidation-Reduction; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D016944:Sulfolobus / Q000737:chemistry / Q000235:genetics; D016945:Sulfolobus acidocaldarius / Q000737:chemistry* / Q000235:genetics
chemical_list: D003573:Cytochrome b Group; C020730:cytochrome b566; C036888:cytochrome b558; D019255:NADPH Oxidases