A common coupling mechanism for A-type heme-copper oxidases from bacteria to mitochondria.
Proc Natl Acad Sci U S A
; 117(17): 9349-9355, 2020 04 28.
Article
em En
| MEDLINE
| ID: mdl-32291342
ABSTRACT
Mitochondria metabolize almost all the oxygen that we consume, reducing it to water by cytochrome c oxidase (CcO). CcO maximizes energy capture into the protonmotive force by pumping protons across the mitochondrial inner membrane. Forty years after the H+/e- stoichiometry was established, a consensus has yet to be reached on the route taken by pumped protons to traverse CcO's hydrophobic core and on whether bacterial and mitochondrial CcOs operate via the same coupling mechanism. To resolve this, we exploited the unique amenability to mitochondrial DNA mutagenesis of the yeast Saccharomyces cerevisiae to introduce single point mutations in the hydrophilic pathways of CcO to test function. From adenosine diphosphate to oxygen ratio measurements on preparations of intact mitochondria, we definitely established that the D-channel, and not the H-channel, is the proton pump of the yeast mitochondrial enzyme, supporting an identical coupling mechanism in all forms of the enzyme.
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Base de dados:
MEDLINE
Assunto principal:
Oxirredutases
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Complexo IV da Cadeia de Transporte de Elétrons
/
Heme
Idioma:
En
Ano de publicação:
2020
Tipo de documento:
Article