title: The phosphonium ion efflux system of Escherichia coli: relationship to the ethidium efflux system and energetic studies.
abstract: The extent of accumulation of methyltriphenylphosphonium ion by Escherichia coli was shown to be dependent on the permeability of the outer membrane and the activity of an efflux system for this compound. Evidence consistent with the operation of a single efflux system for compounds such as phosphonium ions, phenanthridiniums and flavines is presented. Studies on the energy coupling mechanism for this efflux system indicated that it was driven by the transmembrane proton electrochemical gradient.
authors.forename: M
authors.initials: M
authors.lastname: Midgley
mesh_terms: D004734:Energy Metabolism; D004926:Escherichia coli / Q000378:metabolism*; D004996:Ethidium / Q000378:metabolism*; D005609:Free Radicals; D008564:Membrane Potentials; D009861:Onium Compounds / Q000378:metabolism*; D009943:Organophosphorus Compounds / Q000378:metabolism; D011726:Pyridinium Compounds / Q000378:metabolism; D014320:Triphenylmethyl Compounds / Q000378:metabolism*
chemical_list: D005609:Free Radicals; D009861:Onium Compounds; D009943:Organophosphorus Compounds; D011726:Pyridinium Compounds; D014320:Triphenylmethyl Compounds; C011561:triphenylmethylphosphonium; C025042:2-(dimethylaminostyryl)-1-ethylpyridinium; D004996:Ethidium; C013289:tetraphenylphosphonium