CCME, a nuclear-encoded heme-binding protein involved in cytochrome c maturation in plant mitochondria.
J Biol Chem
; 276(8): 5491-7, 2001 Feb 23.
Article
en En
| MEDLINE
| ID: mdl-11069919
The maturation of c-type cytochromes requires the covalent attachment of the heme cofactor to the apoprotein. For this process, plant mitochondria follow a pathway distinct from that of animal or yeast mitochondria, closer to that found in alpha- and gamma-proteobacteria. We report the first characterization of a nuclear-encoded component, namely AtCCME, the Arabidopsis thaliana orthologue of CcmE, a periplasmic heme chaperone in bacteria. AtCCME is targeted to mitochondria, and its N-terminal signal peptide is cleaved upon import. AtCCME is a peripheral protein of the mitochondrial inner membrane, and its major hydrophilic domain is oriented toward the intermembrane space. Although a AtCCME (Met(79)-Ser(256)) is not fully able to complement an Escherichia coli CcmE mutant strain for bacterial holocytochrome c production, it is able to bind heme covalently through a conserved histidine, a feature previously shown for E. coli CcmE. Our results suggest that AtCCME is important for cytochrome c maturation in A. thaliana mitochondria and that its heme-binding function has been conserved evolutionary between land plant mitochondria and alpha-proteobacteria.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas Nucleares
/
Arabidopsis
/
Grupo Citocromo c
/
Proteínas de Arabidopsis
/
Hemo
/
Hemoproteínas
/
Mitocondrias
Idioma:
En
Revista:
J Biol Chem
Año:
2001
Tipo del documento:
Article
País de afiliación:
Francia
Pais de publicación:
Estados Unidos