title: Transmembrane proton translocation by cytochrome c oxidase.
abstract: Respiratory heme-copper oxidases are integral membrane proteins that catalyze the reduction of molecular oxygen to water using electrons donated by either quinol (quinol oxidases) or cytochrome c (cytochrome c oxidases, CcOs). Even though the X-ray crystal structures of several heme-copper oxidases and results from functional studies have provided significant insights into the mechanisms of O2 -reduction and, electron and proton transfer, the design of the proton-pumping machinery is not known. Here, we summarize the current knowledge on the identity of the structural elements involved in proton transfer in CcO. Furthermore, we discuss the order and timing of electron-transfer reactions in CcO during O2 reduction and how these reactions might be energetically coupled to proton pumping across the membrane.
authors.affiliation: Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, Stockholm, Sweden.
authors.forename: Gisela
authors.initials: G
authors.lastname: Brändén
authors.forename: Robert B
authors.initials: RB
authors.lastname: Gennis
authors.forename: Peter
authors.initials: P
authors.lastname: Brzezinski
mesh_terms: D001692:Biological Transport; D002384:Catalysis; D002462:Cell Membrane / Q000201:enzymology*; D003576:Electron Transport Complex IV / Q000737:chemistry* / Q000378:metabolism*; D007700:Kinetics; D008958:Models, Molecular; D010088:Oxidoreductases / Q000737:chemistry / Q000378:metabolism; D011487:Protein Conformation; D011522:Protons
chemical_list: D011522:Protons; D010088:Oxidoreductases; C020094:duroquinol oxidase; D003576:Electron Transport Complex IV