Cross-species chimeras reveal BamA POTRA and ß-barrel domains must be fine-tuned for efficient OMP insertion.
Mol Microbiol
; 97(4): 646-59, 2015 Aug.
Article
en En
| MEDLINE
| ID: mdl-25943387
ABSTRACT
BAM is a conserved molecular machine, the central component of which is BamA. Orthologues of BamA are found in all Gram-negative bacteria, chloroplasts and mitochondria where it is required for the folding and insertion of ß-barrel containing integral outer membrane proteins (OMPs) into the outer membrane. BamA binds unfolded ß-barrel precursors via the five polypeptide transport-associated (POTRA) domains at its N-terminus. The C-terminus of BamA folds into a ß-barrel domain, which tethers BamA to the outer membrane and is involved in OMP insertion. BamA orthologues are found in all Gram-negative bacteria and appear to function in a species-specific manner. Here we investigate the nature of this species-specificity by examining whether chimeric Escherichia coliâ
BamA fusion proteins, carrying either the ß-barrel or POTRA domains from various BamA orthologues, can functionally replace E. coliâ
BamA. We demonstrate that the ß-barrel domains of many BamA orthologues are functionally interchangeable. We show that defects in the orthologous POTRA domains can be rescued by compensatory mutations within the ß-barrel. These data reveal that the POTRA and barrel domains must be precisely aligned to ensure efficient OMP insertion.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Proteínas de la Membrana Bacteriana Externa
/
Proteínas de Escherichia coli
/
Bacterias Gramnegativas
Idioma:
En
Revista:
Mol Microbiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Año:
2015
Tipo del documento:
Article
País de afiliación:
Reino Unido