Binding of the Covalent Flavin Assembly Factor to the Flavoprotein Subunit of Complex II.
J Biol Chem
; 291(6): 2904-16, 2016 Feb 05.
Article
en En
| MEDLINE
| ID: mdl-26644464
ABSTRACT
Escherichia coli harbors two highly conserved homologs of the essential mitochondrial respiratory complex II (succinateubiquinone oxidoreductase). Aerobically the bacterium synthesizes succinatequinone reductase as part of its respiratory chain, whereas under microaerophilic conditions, the quinolfumarate reductase can be utilized. All complex II enzymes harbor a covalently bound FAD co-factor that is essential for their ability to oxidize succinate. In eukaryotes and many bacteria, assembly of the covalent flavin linkage is facilitated by a small protein assembly factor, termed SdhE in E. coli. How SdhE assists with formation of the covalent flavin bond and how it binds the flavoprotein subunit of complex II remain unknown. Using photo-cross-linking, we report the interaction site between the flavoprotein of complex II and the SdhE assembly factor. These data indicate that SdhE binds to the flavoprotein between two independently folded domains and that this binding mode likely influences the interdomain orientation. In so doing, SdhE likely orients amino acid residues near the dicarboxylate and FAD binding site, which facilitates formation of the covalent flavin linkage. These studies identify how the conserved SdhE assembly factor and its homologs participate in complex II maturation.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Proteínas de Escherichia coli
/
Complejo II de Transporte de Electrones
/
Escherichia coli
/
Flavina-Adenina Dinucleótido
Tipo de estudio:
Prognostic_studies
Idioma:
En
Año:
2016
Tipo del documento:
Article