Role of DegP for two-partner secretion in Bordetella.
Mol Microbiol
; 74(2): 315-29, 2009 Oct.
Article
em En
| MEDLINE
| ID: mdl-19703106
ABSTRACT
Sorting of proteins destined to the surface or the extracellular milieu is mediated by specific machineries, which guide the protein substrates towards the proper route of secretion and determine the compartment in which folding occurs. In gram-negative bacteria, the two-partner secretion (TPS) pathway is dedicated to the secretion of large proteins rich in beta-helical structure. The secretion of the filamentous haemagglutinin (FHA), a 230 kDa adhesin of Bordetella pertussis, represents a model TPS system. FHA is exported by the Sec machinery and transits through the periplasm in an extended conformation. From there it is translocated across the outer membrane by its dedicated transporter FhaC to finally fold into a long beta-helix at the cell surface in a progressive manner. In this work, we show that B. pertussis lacking the periplasmic chaperone/protease DegP has a strong growth defect at 37 degrees C, and the integrity of its outer membrane is compromised. While both phenotypes are significantly aggravated by the presence of FHA, the chaperone activity of DegP markedly alleviates the periplasmic stress. In vitro, DegP binds to non-native FHA with high affinity. We propose that DegP chaperones the extended FHA polypeptide in the periplasm and is thus involved in the TPS pathway.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Bordetella pertussis
/
Fatores de Virulência de Bordetella
/
Serina Endopeptidases
/
Adesinas Bacterianas
/
Proteínas Periplásmicas
/
Proteínas de Choque Térmico
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Mol Microbiol
Assunto da revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Ano de publicação:
2009
Tipo de documento:
Article
País de afiliação:
França