» Articles » PMID: 32015551

Atomic Structures of Closed and Open Influenza B M2 Proton Channel Reveal the Conduction Mechanism

Overview
Date 2020 Feb 5
PMID 32015551
Citations 36
Authors
Affiliations
Soon will be listed here.
Abstract

The influenza B M2 (BM2) proton channel is activated by acidic pH to mediate virus uncoating. Unlike influenza A M2 (AM2), which conducts protons with strong inward rectification, BM2 conducts protons both inward and outward. Here we report 1.4- and 1.5-Å solid-state NMR structures of the transmembrane domain of the closed and open BM2 channels in a phospholipid environment. Upon activation, the transmembrane helices increase the tilt angle by 6° and the average pore diameter enlarges by 2.1 Å. BM2 thus undergoes a scissor motion for activation, which differs from the alternating-access motion of AM2. These results indicate that asymmetric proton conduction requires a backbone hinge motion, whereas bidirectional conduction is achieved by a symmetric scissor motion. The proton-selective histidine and gating tryptophan in the open BM2 reorient on the microsecond timescale, similar to AM2, indicating that side chain dynamics are the essential driver of proton shuttling.

Citing Articles

OPTO: Automated Optimization for Solid-State NMR Spectroscopy.

Borcik C, DeZonia B, Ravula T, Harding B, Garg R, Rienstra C J Am Chem Soc. 2025; 147(4):3293-3303.

PMID: 39814553 PMC: 11808819. DOI: 10.1021/jacs.4c13295.


Activation of the Influenza B M2 Proton Channel (BM2).

Yue Z, Wu J, Teng D, Wang Z, Voth G Biochemistry. 2024; 63(22):3011-3019.

PMID: 39488842 PMC: 11580745. DOI: 10.1021/acs.biochem.4c00607.


Guidelines for naming and studying plasma membrane domains in plants.

Jaillais Y, Bayer E, Bergmann D, Botella M, Boutte Y, Bozkurt T Nat Plants. 2024; 10(8):1172-1183.

PMID: 39134664 DOI: 10.1038/s41477-024-01742-8.


Activation of the influenza B M2 proton channel (BM2).

Yue Z, Wu J, Teng D, Wang Z, Voth G bioRxiv. 2024; .

PMID: 39091734 PMC: 11291123. DOI: 10.1101/2024.07.26.605324.


Structure and dynamics of the proton-selective histidine and the gating tryptophan in an inward rectifying hybrid influenza B and A virus M2 proton channel.

Pankratova Y, McKay M, Ma C, Tan H, Wang J, Hong M Phys Chem Chem Phys. 2024; 26(30):20629-20644.

PMID: 39037444 PMC: 11290064. DOI: 10.1039/d4cp01648c.


References
1.
Liang R, Swanson J, Madsen J, Hong M, DeGrado W, Voth G . Acid activation mechanism of the influenza A M2 proton channel. Proc Natl Acad Sci U S A. 2016; 113(45):E6955-E6964. PMC: 5111692. DOI: 10.1073/pnas.1615471113. View

2.
Ivanovic T, Rozendaal R, Floyd D, Popovic M, van Oijen A, Harrison S . Kinetics of proton transport into influenza virions by the viral M2 channel. PLoS One. 2012; 7(3):e31566. PMC: 3295812. DOI: 10.1371/journal.pone.0031566. View

3.
Mitchell P . A general theory of membrane transport from studies of bacteria. Nature. 1957; 180(4577):134-6. DOI: 10.1038/180134a0. View

4.
Bak , Nielsen . REPULSION, A Novel Approach to Efficient Powder Averaging in Solid-State NMR. J Magn Reson. 1997; 125(1):132-9. DOI: 10.1006/jmre.1996.1087. View

5.
Wang J, Pielak R, McClintock M, Chou J . Solution structure and functional analysis of the influenza B proton channel. Nat Struct Mol Biol. 2009; 16(12):1267-71. PMC: 3148584. DOI: 10.1038/nsmb.1707. View