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Publication Abstract from PubMed

The Fluc family of F(-) ion channels protects prokaryotes and lower eukaryotes from the toxicity of environmental F(-). In bacteria, these channels are built as dual-topology dimers whereby the two subunits assemble in antiparallel transmembrane orientation. Recent crystal structures suggested that Fluc channels contain two separate ion-conduction pathways, each with two F(-) binding sites, but no functional correlates of this unusual architecture have been reported. Experiments here fill this gap by examining the consequences of mutating two conserved F(-)-coordinating phenylalanine residues. Substitution of each phenylalanine specifically extinguishes its associated F(-) binding site in crystal structures and concomitantly inhibits F(-) permeation. Functional analysis of concatemeric channels, which permit mutagenic manipulation of individual pores, show that each pore can be separately inactivated without blocking F(-) conduction through its symmetry-related twin. The results strongly support dual-pathway architecture of Fluc channels.

Mechanistic signs of double-barreled structure in a fluoride ion channel.,Last NB, Kolmakova-Partensky L, Shane T, Miller C Elife. 2016 Jul 23;5. pii: e18767. doi: 10.7554/eLife.18767. PMID:27449280^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.