Editors' ChoiceBiochemistry

M2 Out of the Envelope

Science Signaling  26 Oct 2010:
Vol. 3, Issue 145, pp. ec331
DOI: 10.1126/scisignal.3145ec331

The M2 protein from influenza A virus forms an acid-activated tetrameric proton channel in the viral envelope and is essential for viral replication. Two manuscripts shed light on the functional mechanism of this channel. Sharma et al. (see the Perspective by Fiorin et al.) determined the structure of the conductance domain in a lipid bilayer and propose that a histidine and tryptophan from each monomer form a cluster that guides protons through the channel in a mechanism that involves forming and breaking hydrogen bonds between adjacent pairs of histidines. Hu et al. (see the Perspective by Fiorin et al.) focused on the structure and dynamics of the proton-selective histidine at high and low pH, proposing that proton conduction involves histidine deprotonation and reprotonation.

M. Sharma, M. Yi, H. Dong, H. Qin, E. Peterson, D. D. Busath, H.-X. Zhou, T. A. Cross, Insight into the mechanism of the influenza A proton channel from a structure in a lipid bilayer. Science 330, 509–512 (2010). [Abstract] [Full Text]

F. Hu, W. Luo, M. Hong, Mechanisms of proton conduction and gating in influenza M2 proton channels from solid-state NMR. Science 330, 505–508 (2010). [Abstract] [Full Text]

G. Fiorin, V. Carnevale, W. F. DeGrado, The flu’s proton escort. Science 330, 456–458 (2010). [Abstract] [Full Text]