title: An aqueous channel for filamentous phage export.
abstract: Filamentous phage f1 exits its Escherichia coli host without killing the bacterial cell. It has been proposed that f1 is secreted through the outer membrane via a phage-encoded channel protein, pIV. A functional pIV mutant was isolated that allowed E. coli to grow on large maltodextrins and rendered E. coli sensitive to large hydrophilic antibiotics that normally do not penetrate the outer membrane. In planar lipid bilayers, both mutant and wild-type pIV formed highly conductive channels with similar permeability characteristics but different gating properties: the probability of the wild-type channel being open was much less than that of the mutant channel. The high conductivity of pIV channels suggests a large-diameter pore, thus implicating pIV as the outer membrane phage-conducting channel.
authors.affiliation: The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA.
authors.forename: D K
authors.initials: DK
authors.lastname: Marciano
authors.forename: M
authors.initials: M
authors.lastname: Russel
authors.forename: S M
authors.initials: SM
authors.lastname: Simon
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001692:Biological Transport; D050260:Carbohydrate Metabolism; D002462:Cell Membrane / Q000378:metabolism; D002463:Cell Membrane Permeability; D003090:Coliphages / Q000378:metabolism*; D004553:Electric Conductivity; D004594:Electrophysiology; D004926:Escherichia coli / Q000378:metabolism / Q000821:virology*; D017912:Inovirus / Q000378:metabolism*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000378:metabolism*; D008051:Lipid Bilayers; D008565:Membrane Proteins / Q000378:metabolism*; D009154:Mutation; D011134:Polysaccharides / Q000378:metabolism; D018272:Porins / Q000378:metabolism; D011510:Proteolipids; D014640:Vancomycin / Q000494:pharmacology; D017361:Viral Nonstructural Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D007473:Ion Channels; D008051:Lipid Bilayers; D008565:Membrane Proteins; D011134:Polysaccharides; D018272:Porins; D011510:Proteolipids; D017361:Viral Nonstructural Proteins; C119520:pIV protein, Enterobacteria phage f1; C020485:proteoliposomes; D014640:Vancomycin; C008315:maltodextrin