TY - JOUR
T1 - Proton transfer in ba 3 cytochrome c oxidase from Thermus thermophilus
AU - Von Ballmoos, Christoph
AU - Ädelroth, Pia
AU - Gennis, Robert B.
AU - Brzezinski, Peter
N1 - Funding Information:
Part of the studies described in this review was supported by grants from the Swedish Research Council (to PB and PÄ), and by grant HL 16101 from the National Institutes of Health (to RBG.). CvB is supported by a fellowship from the Swiss National Science Foundation (SNF) . PÄ is a Royal Swedish Academy of Sciences Research Fellow supported by a grant from the Knut and Alice Wallenberg Foundation .
PY - 2012/4
Y1 - 2012/4
N2 - The respiratory heme-copper oxidases catalyze reduction of O 2 to H 2O, linking this process to transmembrane proton pumping. These oxidases have been classified according to the architecture, location and number of proton pathways. Most structural and functional studies to date have been performed on the A-class oxidases, which includes those that are found in the inner mitochondrial membrane and bacteria such as Rhodobacter sphaeroides and Paracoccus denitrificans (aa 3-type oxidases in these bacteria). These oxidases pump protons with a stoichiometry of one proton per electron transferred to the catalytic site. The bacterial A-class oxidases use two proton pathways (denoted by letters D and K, respectively), for the transfer of protons to the catalytic site, and protons that are pumped across the membrane. The B-type oxidases such as, for example, the ba 3 oxidase from Thermus thermophilus, pump protons with a lower stoichiometry of 0.5 H +/electron and use only one proton pathway for the transfer of all protons. This pathway overlaps in space with the K pathway in the A class oxidases without showing any sequence homology though. Here, we review the functional properties of the A- and the B-class ba 3 oxidases with a focus on mechanisms of proton transfer and pumping. This article is part of a Special Issue entitled: Respiratory Oxidases.
AB - The respiratory heme-copper oxidases catalyze reduction of O 2 to H 2O, linking this process to transmembrane proton pumping. These oxidases have been classified according to the architecture, location and number of proton pathways. Most structural and functional studies to date have been performed on the A-class oxidases, which includes those that are found in the inner mitochondrial membrane and bacteria such as Rhodobacter sphaeroides and Paracoccus denitrificans (aa 3-type oxidases in these bacteria). These oxidases pump protons with a stoichiometry of one proton per electron transferred to the catalytic site. The bacterial A-class oxidases use two proton pathways (denoted by letters D and K, respectively), for the transfer of protons to the catalytic site, and protons that are pumped across the membrane. The B-type oxidases such as, for example, the ba 3 oxidase from Thermus thermophilus, pump protons with a lower stoichiometry of 0.5 H +/electron and use only one proton pathway for the transfer of all protons. This pathway overlaps in space with the K pathway in the A class oxidases without showing any sequence homology though. Here, we review the functional properties of the A- and the B-class ba 3 oxidases with a focus on mechanisms of proton transfer and pumping. This article is part of a Special Issue entitled: Respiratory Oxidases.
KW - Electrochemical gradient
KW - Electron transfer
KW - Energy conservation
KW - Kinetics
KW - Membrane protein
KW - Respiratory oxidase
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U2 - 10.1016/j.bbabio.2011.11.015
DO - 10.1016/j.bbabio.2011.11.015
M3 - Review article
C2 - 22172736
AN - SCOPUS:84857915374
SN - 0005-2728
VL - 1817
SP - 650
EP - 657
JO - Biochimica et Biophysica Acta - Bioenergetics
JF - Biochimica et Biophysica Acta - Bioenergetics
IS - 4
ER -