|
|
|
|
|
|
|
Free Newsletters
Archive
My Subscriptions
News by Subject
News by Disease
News by Date
PLoS
Search News
Post Your News
JoVE
Job Seeker Login
Most Recent Jobs
Browse Biotech Jobs
Search Jobs
Post Resume
Career Fairs
Career Resources
For Employers
Regional News
US & Canada
Biotech Bay
Biotech Beach
Genetown
Pharm Country
BioCapital
BioMidwest
Bio NC
BioForest
Southern Pharm
BioCanada East
US Device
Europe
Asia
Market Summary
News
IPOs
Company Profiles
Companies
Events
Research Store
Biotech Events
Post an Event
Real Estate
Business Opportunities
|
|
|
|
PLoS By Category | Recent
PLoS Articles
|
|
Biochemistry - Microbiology
|
Membrane Fusion Proteins of Type I Secretion System and Tripartite Efflux Pumps Share a Binding Motif for TolC in Gram-Negative Bacteria
Published:
Friday, July 06, 2012
Author:
Minho Lee et al.
by Minho Lee, So-Young Jun, Bo-Young Yoon, Saemee Song, Kangseok Lee, Nam-Chul Ha
The Hly translocator complex of Escherichia coli catalyzes type I secretion of the toxin hemolysin A (HlyA). In this complex, HlyB is an inner membrane ABC (ATP Binding Cassette)-type transporter, TolC is an outer membrane channel protein, and HlyD is a periplasmic adaptor anchored in the inner membrane that bridges HlyB to TolC. This tripartite organization is reminiscent of that of drug efflux systems such as AcrA-AcrB-TolC and MacA-MacB-TolC of E. coli. We have previously shown the crucial role of conserved residues located at the hairpin tip region of AcrA and MacA adaptors during assembly of their cognate systems. In this study, we investigated the role of the putative tip region of HlyD using HlyD mutants with single amino acid substitutions at the conserved positions. In vivo and in vitro data show that all mutations abolished HlyD binding to TolC and resulted in the absence of HlyA secretion. Together, our results suggest that, similarly to AcrA and MacA, HlyD interacts with TolC in a tip-to-tip manner. A general model in which these conserved interactions induce opening of TolC during drug efflux and type I secretion is discussed.
More...
|
|
|
 |
|
|
|
|
|
|
|
|