1. Role of the constriction loop in the gating of outer membrane porin PhoE of Escherichia coli.
- Author
-
Eppens EF, Saint N, Van Gelder P, van Boxtel R, and Tommassen J
- Subjects
- Anti-Bacterial Agents metabolism, Cloning, Molecular, Electric Conductivity, Escherichia coli metabolism, Escherichia coli Proteins, Lactams, Liposomes metabolism, Models, Molecular, Mutation, Porins genetics, Protein Conformation, Protein Structure, Secondary, Escherichia coli chemistry, Ion Channel Gating physiology, Porins chemistry, Porins metabolism
- Abstract
Porins form voltage-gated channels in the bacterial outer membrane. These proteins are composed of three identical subunits, each forming a 16-stranded beta-barrel. In this study, the role in voltage gating of a loop that forms a constriction within the pore was studied. The channel characteristics of mutant PhoE porins, in which the tip of the constriction loop was connected to the barrel wall, were determined. Whereas the properties of several mutant channels were changed, all of these channels could still be closed at high potential, showing that a gross movement of the constriction loop within the channel is not implicated in voltage gating.
- Published
- 1997
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