Homologous bd oxidases share the same architecture but differ in mechanism.
Nat Commun
; 10(1): 5138, 2019 11 13.
Article
en En
| MEDLINE
| ID: mdl-31723136
Cytochrome bd oxidases are terminal reductases of bacterial and archaeal respiratory chains. The enzyme couples the oxidation of ubiquinol or menaquinol with the reduction of dioxygen to water, thus contributing to the generation of the protonmotive force. Here, we determine the structure of the Escherichia coli bd oxidase treated with the specific inhibitor aurachin by cryo-electron microscopy (cryo-EM). The major subunits CydA and CydB are related by a pseudo two fold symmetry. The heme b and d cofactors are found in CydA, while ubiquinone-8 is bound at the homologous positions in CydB to stabilize its structure. The architecture of the E. coli enzyme is highly similar to that of Geobacillus thermodenitrificans, however, the positions of heme b595 and d are interchanged, and a common oxygen channel is blocked by a fourth subunit and substituted by a more narrow, alternative channel. Thus, with the same overall fold, the homologous enzymes exhibit a different mechanism.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Oxidorreductasas
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Homología de Secuencia de Aminoácido
/
Grupo Citocromo b
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Proteínas de Escherichia coli
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Proteínas del Complejo de Cadena de Transporte de Electrón
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Escherichia coli
Idioma:
En
Revista:
Nat Commun
Asunto de la revista:
BIOLOGIA
/
CIENCIA
Año:
2019
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Reino Unido