Simulations of the BM2 proton channel transmembrane domain from influenza virus B.
BM2 is a small integral membrane protein from influenza B virus which forms proton-permeable channels. Coarse-grained (CG) molecular dynamics simulations have been used to produce a model of the BM2 channel by self-assembly of a tetrameric bundle of BM2 transmembrane helices in a lipid bilayer. The BM2 channel model is conformationally stable on a 5 mus time scale. This CG model was converted to atomistic resolution to refine interhelix and channel-water interactions. Atomistic molecular dynamics simulations indicate that the BM2 channel is closed when no more than two of the four His19 residues are protonated. Protonating a third His19 side chain initiates a conformational change that opens the channel. In summary, our simulations suggest a common mechanism for BM2 and A/M2, whereby changes in helix packing play a functional role in channel gating.
Department of Biochemistry, University of Oxford, Oxford OX1 3QU, UK.
Sarah L
SL
Rouse
Timothy
T
Carpenter
Phillip J
PJ
Stansfeld
Mark S P
MS
Sansom
D003198:Computer Simulation; D009981:Influenza B virus / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry*; D008958:Models, Molecular; D017434:Protein Structure, Tertiary; D014764:Viral Proteins / Q000737:chemistry*
C064964:BM2 polypeptide, influenza B virus; D008565:Membrane Proteins; D014764:Viral Proteins