The amino terminus of Pseudomonas aeruginosa outer membrane protein OprF forms channels in lipid bilayer membranes: correlation with a three-dimensional model |
| |
| Authors: | Brinkman F S Bains M Hancock R E |
| |
| Affiliation: | Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada. |
| |
| Abstract: | Pseudomonas aeruginosa OprF forms 0.36-nS channels and, rarely, 2- to 5-nS channels in lipid bilayer membranes. We show that a protein comprising only the N-terminal 162-amino-acid domain of OprF formed the smaller, but not the larger, channels in lipid bilayers. Circular dichroism spectroscopy indicated that this protein folds into a beta-sheet-rich structure, and three-dimensional comparative modeling revealed that it shares significant structural similarity with the amino terminus of the orthologous protein Escherichia coli OmpA, which has been shown to form a beta-barrel. OprF and OmpA share only 15% identity in this domain, yet these results support the utility of modeling such widely divergent beta-barrel domains in three dimensions in order to reveal similarities not readily apparent through primary sequence comparisons. The model is used to further hypothesize why porin activity differs for the N-terminal domains of OprF and OmpA. |
| |
| Keywords: | |
| 本文献已被 PubMed 等数据库收录！ |
|
