title: Conformation of the c552:aa3 electron transfer complex in Paracoccus denitrificans studied by EPR on oriented samples.
abstract: The EPR spectral parameters of aa(3) oxidase and cyt c(552) from Paracoccus denitrificans were studied in purified oxidase and enriched cyt c(552). The orientation of the g-tensors of hemes a and c(552) were determined on partially ordered membranes, enriched cyt c(552) and a c(552):aa(3) subcomplex. The known correlation of g-tensor to molecular axes in histidine/methionine ligated hemes permits us to position cyt c(552) with respect to the parent membrane. Taken together with previous data on the interaction surface between aa(3) oxidase and cyt c(552), these results allow us to arrive at a single conformation for the c(552):aa(3) electron transfer complex.
authors.affiliation: INSERM U696, Laboratory of Optics and Biosciences, Ecole Polytechnique, 91128 Palaiseau Cedex, France.
authors.forename: Gérard
authors.initials: G
authors.lastname: Lipowski
authors.forename: Ursula
authors.initials: U
authors.lastname: Liebl
authors.forename: Bruno
authors.initials: B
authors.lastname: Guigliarelli
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Nitschke
authors.forename: Barbara
authors.initials: B
authors.lastname: Schoepp-Cothenet
mesh_terms: D003574:Cytochrome c Group / Q000737:chemistry*; D004578:Electron Spin Resonance Spectroscopy; D004579:Electron Transport; D003576:Electron Transport Complex IV / Q000737:chemistry; D006418:Heme / Q000737:chemistry; D008958:Models, Molecular; D015394:Molecular Structure; D046912:Multiprotein Complexes; D010231:Paracoccus denitrificans / Q000737:chemistry*; D011487:Protein Conformation
chemical_list: D003574:Cytochrome c Group; D046912:Multiprotein Complexes; D006418:Heme; C022302:cytochrome C-552; D003576:Electron Transport Complex IV