A pH-dependent conformational ensemble mediates proton transport through the influenza A/M2 protein.

ABSTRACT: The influenza A/M2 protein exhibits inwardly rectifying, pH-activated proton transport that saturates at low pH. A comparison of high-resolution structures of the transmembrane domain at high and low pH suggests that pH-dependent conformational changes may facilitate proton conduction by alternately changing the accessibility of the N-terminal and C-terminal regions of the channel as a proton transits through the transmembrane domain. Here, we show that M2 functionally reconstituted in liposomes populates at least three different conformational states over a physiologically relevant pH range, with transition midpoints that are consistent with previously reported His37 pK(a) values. We then develop and test two similar, quantitative mechanistic models of proton transport, where protonation

SUBMITTER: Polishchuk AL 

PROVIDER: S-EPMC3164293 | biostudies-literature | 2010 Nov

REPOSITORIES: biostudies-literature