Back to Search
Start Over
Influence of the passenger domain of a model autotransporter on the properties of its translocator domain.
- Source :
-
Molecular Membrane Biology . May2008, Vol. 25 Issue 3, p192-202. 11p. 1 Black and White Photograph, 1 Diagram, 4 Graphs. - Publication Year :
- 2008
-
Abstract
- Autotransporters are a superfamily of proteins secreted by Gram-negative bacteria including many virulence factors. They are modular proteins composed of an N-terminal signal peptide, a surface-exposed 'passenger' domain carrying the activity of the protein, and a C-terminal 'translocator' domain composed of an α-helical linker region and a transmembrane β-barrel. The translocator domain plays an essential role for the secretion of the passenger domain across the outer membrane; however, the mechanism of autotransport remains poorly understood. The whooping cough agent Bordetella pertussis produces an autotransporter serine-protease, SphB1, which is involved in the maturation of an adhesin at the bacterial surface. SphB1 also mediates the proteolytic maturation of its own precursor. We used SphB1 as a model autotransporter and performed the first comparisons of the biochemical and biophysical properties of an isolated translocator domain with those of the same domain preceded by the C-terminal moiety of its natural passenger. By using cross-linking and dynamic light scattering, we provide evidence that the passenger domain promotes the auto-association of SphB1, although these interactions appear rather labile. Electrophysiological studies revealed that the passenger domain of the autotransporter appears to maintain the translocator channel in a low-conductance conformation, most likely by stabilizing the α-helix inside the pore. That the passenger may significantly influence AT physicochemical properties is likely to be relevant for the in vivo maturation and stability of AT proteins. [ABSTRACT FROM AUTHOR]
- Subjects :
- *BIOMOLECULES
*BACTERIA
*PROTEINS
*AMINO acids
*LIGHT scattering
Subjects
Details
- Language :
- English
- ISSN :
- 09687688
- Volume :
- 25
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Molecular Membrane Biology
- Publication Type :
- Academic Journal
- Accession number :
- 31730586
- Full Text :
- https://doi.org/10.1080/09687680701771925