Signal recognition particle (SRP)-mediated targeting and Sec-dependent translocation of an extracellular Escherichia coli protein.
J Biol Chem
; 278(7): 4654-9, 2003 Feb 14.
Article
em En
| MEDLINE
| ID: mdl-12466262
ABSTRACT
Hemoglobin protease (Hbp) is a hemoglobin-degrading protein that is secreted by a human pathogenic Escherichia coli strain via the autotransporter mechanism. Little is known about the earliest steps in autotransporter secretion, i.e. the targeting to and translocation across the inner membrane. Here, we present evidence that Hbp interacts with the signal recognition particle (SRP) and the Sec-translocon early during biogenesis. Furthermore, Hbp requires a functional SRP targeting pathway and Sec-translocon for optimal translocation across the inner membrane. SecB is not required for targeting of Hbp but can compensate to some extent for the lack of SRP. Hbp is synthesized with an unusually long signal peptide that is remarkably conserved among a subset of autotransporters. We propose that these autotransporters preferentially use the co-translational SRP/Sec route to avoid adverse effects of the exposure of their mature domains in the cytoplasm.
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Bases de dados:
MEDLINE
Assunto principal:
Endopeptidases
/
Proteínas de Bactérias
/
Partícula de Reconhecimento de Sinal
/
Escherichia coli
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2003
Tipo de documento:
Article
País de afiliação:
Holanda