Mitochondria can recognize and assemble fragments of a beta-barrel structure.
Mol Biol Cell
; 22(10): 1638-47, 2011 May 15.
Article
em En
| MEDLINE
| ID: mdl-21460184
ABSTRACT
ß-barrel proteins are found in the outer membranes of eukaryotic organelles of endosymbiotic origin as well as in the outer membrane of Gram-negative bacteria. Precursors of mitochondrial ß-barrel proteins are synthesized in the cytosol and have to be targeted to the organelle. Currently, the signal that assures their specific targeting to mitochondria is poorly defined. To characterize the structural features needed for specific mitochondrial targeting and to test whether a full ß-barrel structure is required, we expressed in yeast cells the ß-barrel domain of the trimeric autotransporter Yersinia adhesin A (YadA). Trimeric autotransporters are found only in prokaryotes, where they are anchored to the outer membrane by a single 12-stranded ß-barrel structure to which each monomer is contributing four ß-strands. Importantly, we found that YadA is solely localized to the mitochondrial outer membrane, where it exists in a native trimeric conformation. These findings demonstrate that, rather than a linear sequence or a complete ß-barrel structure, four ß-strands are sufficient for the mitochondria to recognize and assemble a ß-barrel protein. Remarkably, the evolutionary origin of mitochondria from bacteria enables them to import and assemble even proteins belonging to a class that is absent in eukaryotes.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fragmentos de Peptídeos
/
Proteínas Recombinantes
/
Adesinas Bacterianas
/
Membranas Mitocondriais
/
Mitocôndrias
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Biol Cell
Assunto da revista:
BIOLOGIA MOLECULAR
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Alemanha