cytoplasmic domain structure of BM2 proton channel from influenza B virus

Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history


Solution structure and functional analysis of the influenza B proton channel.

Wang, J.Pielak, R.M.McClintock, M.A.Chou, J.J.

(2009) Nat Struct Mol Biol 16: 1267-1271

  • DOI: https://doi.org/10.1038/nsmb.1707
  • Primary Citation of Related Structures:  
    2KIX, 2KJ1

  • PubMed Abstract: 

    Influenza B virus contains an integral membrane protein, BM2, that oligomerizes in the viral membrane to form a pH-activated proton channel. Here we report the solution structures of both the membrane-embedded channel domain and the cytoplasmic domain of BM2. The channel domain assumes a left-handed coiled-coil tetramer formation with a helical packing angle of -37 degrees to form a polar pore in the membrane for conducting ions. Mutagenesis and proton flux experiments identified residues involved in proton relay and suggest a mechanism of proton conductance. The cytoplasmic domain of BM2 also forms a coiled-coil tetramer. It has a bipolar charge distribution, in which a negatively charged region interacts specifically with the M1 matrix protein that is involved in packaging the genome in the virion. This interaction suggests BM2 also recruits matrix proteins to the cell surface during virus budding, making BM2 an unusual membrane protein with the dual roles of conducting ions and recruiting proteins to the membrane.

  • Organizational Affiliation

    Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
BM2 protein
A, B, C, D
89Influenza B virusMutation(s): 0 
Gene Names: BM2
Membrane Entity: Yes 
Find proteins for Q9WD75 (Influenza B virus)
Explore Q9WD75 
Go to UniProtKB:  Q9WD75
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9WD75
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 100 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-11-10
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2022-03-16
    Changes: Data collection, Database references, Derived calculations