PMID:15465872
| Citation |
Zakharov, SD, Eroukova, VY, Rokitskaya, TI, Zhalnina, MV, Sharma, O, Loll, PJ, Zgurskaya, HI, Antonenko, YN and Cramer, WA (2004) Colicin occlusion of OmpF and TolC channels: outer membrane translocons for colicin import. Biophys. J. 87:3901-11 |
|---|---|
| Abstract |
The interaction of colicins with target cells is a paradigm for protein import. To enter cells, bactericidal colicins parasitize Escherichia coli outer membrane receptors whose physiological purpose is the import of essential metabolites. Colicins E1 and E3 initially bind to the BtuB receptor, whose beta-barrel pore is occluded by an N-terminal globular "plug". The x-ray structure of a complex of BtuB with the coiled-coil BtuB-binding domain of colicin E3 did not reveal displacement of the BtuB plug that would allow passage of the colicin (Kurisu, G., S. D. Zakharov, M. V. Zhalnina, S. Bano, V. Y. Eroukova, T. I. Rokitskaya, Y. N. Antonenko, M. C. Wiener, and W. A. Cramer. 2003. Nat. Struct. Biol. 10:948-954). This correlates with the inability of BtuB to form ion channels in planar bilayers, shown in this work, suggesting that an additional outer membrane protein(s) is required for colicin import across the outer membrane. The identity and interaction properties of this OMP were analyzed in planar bilayer experiments.OmpF and TolC channels in planar bilayers were occluded by colicins E3 and E1, respectively, from the trans-side of the membrane. Occlusion was dependent upon a cis-negative transmembrane potential. A positive potential reversibly opened OmpF and TolC channels. Colicin N, which uses only OmpF for entry, occludes OmpF in planar bilayers with the same orientation constraints as colicins E1 and E3. The OmpF recognition sites of colicins E3 and N, and the TolC recognition site of colicin E1, were found to reside in the N-terminal translocation domains. These data are considered in the context of a two-receptor translocon model for colicin entry into cells. |
| Links |
PubMed PMC1304901 Online version:10.1529/biophysj.104.046151 |
| Keywords |
Bacterial Outer Membrane Proteins/chemistry; Colicins/chemistry; Diffusion; Escherichia coli Proteins/metabolism; Ion Channel Gating; Lipid Bilayers/chemistry; Membrane Transport Proteins; Membranes, Artificial; Porins/chemistry; Protein Binding; Protein Transport; Receptors, Peptide/metabolism |
| edit table |
Significance
You can help EcoliWiki by summarizing why this paper is useful
Useful Materials and Methods
You can help Ecoliwiki by describing the useful materials (strains, plasmids, antibodies, etc) described in this paper.
Annotations
<annotationlinks/>
EcoliWiki Links
Add links to pages that link here (e.g. gene, product, method pages)
References
See Help:References for how to manage references in EcoliWiki.