Enzymatic activity of the alternative complex III as a menaquinol:auracyanin oxidoreductase in the electron transfer chain of Chloroflexus aurantiacus.
FEBS Lett
; 583(19): 3275-9, 2009 Oct 06.
Article
em En
| MEDLINE
| ID: mdl-19755122
ABSTRACT
The surprising lack of the cytochrome bc1 complex in the filamentous anoxygenic phototrophic bacterium Chloroflexus aurantiacus suggests that a functional replacement exists to link the cyclic electron transfer chain. Earlier work identified the alternative complex III (ACIII) as a substitute of cytochrome bc1 complex. Herein, the enzymatic activity of ACIII is studied. The results strongly support the view that the ACIII functions as menaquinolauracyanin oxidoreductase in the C. aurantiacus electron transfer chain. Among all the substrates tested, auracyanin is the most efficient electron acceptor of ACIII, suggesting that ACIII directly transfers the electron to auracyanin instead of cytochrome c-554. The lack of sensitivity to common inhibitors of the cytochrome bc1 complex indicates a different catalytic mechanism for the ACIII complex.
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Quinona Redutases
/
Proteínas de Bactérias
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Complexo III da Cadeia de Transporte de Elétrons
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Vitamina K 2
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Chloroflexus
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Metaloproteínas
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article