High-conductance channel induced by the interaction of phage lambda with its receptor maltoporin

Bacteriophage lambda that binds to liposomes bears its receptor maltoporin (LamB) and is able to inject its DNA into the internal space. During this process, the liposomes are permeabilized, suggesting that a transmembrane channel has formed (Roessner and Ihler (1986) J. Biol. Chem. 261, 386-390). This pore possibly constitutes the pathway used by lambda DNA to cross the membrane. We reconstituted purified LamB from Shigella in liposomes that were incubated with lambda phages, Addition of this mixture to a bilayer chamber resulted in the incorporation in planar bilayers of high-conductance channels whose conductance, kinetics and voltage dependence were totally different from those of maltoporin channels. (C) 2000 Federation of European Biochemical Societies, Published by Elsevier Science B.V. All rights reserved.