Insights into proton translocation in cbb3 oxidase from MD simulations.
Biochim Biophys Acta Bioenerg
; 1858(5): 396-406, 2017 May.
Article
de En
| MEDLINE
| ID: mdl-28259641
ABSTRACT
Heme-copper oxidases are membrane protein complexes that catalyse the final step of the aerobic respiration, namely the reduction of oxygen to water. The energy released during catalysis is coupled to the active translocation of protons across the membrane, which contributes to the establishment of an electrochemical gradient that is used for ATP synthesis. The distinctive C-type (or cbb3) cytochrome c oxidases, which are mostly present in proteobacteria, exhibit a number of unique structural and functional features, including high catalytic activity at low oxygen concentrations. At the moment, the functioning mechanism of C-type oxidases, in particular the proton transfer/pumping mechanism presumably via a single proton channel, is still poorly understood. In this work we used all-atom molecular dynamics simulations and continuum electrostatics calculations to obtain atomic-level insights into the hydration and dynamics of a cbb3 oxidase. We provide the details of the water dynamics and proton transfer pathways for both the "chemical" and "pumped" protons, and show that formation of protonic connections is strongly affected by the protonation state of key residues, namely H243, E323 and H337.
Mots clés
Texte intégral:
1
Collection:
01-internacional
Base de données:
MEDLINE
Sujet principal:
Protéines bactériennes
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Pompes à protons
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Complexe IV de la chaîne respiratoire
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Pseudomonas stutzeri
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Métabolisme énergétique
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Simulation de dynamique moléculaire
Langue:
En
Journal:
Biochim Biophys Acta Bioenerg
Année:
2017
Type de document:
Article