Magic-Angle-Spinning Solid-State NMR Structure of Influenza A M2 Transmembrane Domain

Experimental Data Snapshot

  • Conformers Calculated: 
  • Conformers Submitted: 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation   3D Report Full Report

This is version 1.2 of the entry. See complete history

Re-refinement Note

A newer entry is available that reflects an alternative modeling of the original data: 2KQT


Structure of amantadine-bound M2 transmembrane peptide of influenza A in lipid bilayers from magic-angle-spinning solid-state NMR: the role of Ser31 in amantadine binding.

Cady, S.D.Mishanina, T.V.Hong, M.

(2009) J Mol Biol 385: 1127-1141

  • DOI: https://doi.org/10.1016/j.jmb.2008.11.022
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    The M2 proton channel of influenza A is the target of the antiviral drugs amantadine and rimantadine, whose effectiveness has been abolished by a single-site mutation of Ser31 to Asn in the transmembrane domain of the protein. Recent high-resolution structures of the M2 transmembrane domain obtained from detergent-solubilized protein in solution and crystal environments gave conflicting drug binding sites. We present magic-angle-spinning solid-state NMR results of Ser31 and a number of other residues in the M2 transmembrane peptide (M2TMP) bound to lipid bilayers. Comparison of the spectra of the membrane-bound apo and complexed M2TMP indicates that Ser31 is the site of the largest chemical shift perturbation by amantadine. The chemical shift constraints lead to a monomer structure with a small kink of the helical axis at Gly34. A tetramer model is then constructed using the helix tilt angle and several interhelical distances previously measured on unoriented bilayer samples. This tetramer model differs from the solution and crystal structures in terms of the openness of the N-terminus of the channel, the constriction at Ser31, and the side-chain conformations of Trp41, a residue important for channel gating. Moreover, the tetramer model suggests that Ser31 may interact with amantadine amine via hydrogen bonding. While the apo and drug-bound M2TMP have similar average structures, the complexed peptide has much narrower linewidths at physiological temperature, indicating drug-induced changes of the protein dynamics in the membrane. Further, at low temperature, several residues show narrower lines in the complexed peptide than the apo peptide, indicating that amantadine binding reduces the conformational heterogeneity of specific residues. The differences of the current solid-state NMR structure of the bilayer-bound M2TMP from the detergent-based M2 structures suggest that the M2 conformation is sensitive to the environment, and care must be taken when interpreting structural findings from non-bilayer samples.

  • Organizational Affiliation

    Department of Chemistry, Iowa State University, Ames, IA 50011, USA.


Find similar proteins by:  Sequence   |   3D Structure  

Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Transmembrane peptide of Matrix protein 2
A, B, C, D
25N/AMutation(s): 1 
Membrane Entity: Yes 
Find proteins for O70632 (Influenza A virus (strain A/Hong Kong/156/1997 H5N1 genotype Gs/Gd))
Explore O70632 
Go to UniProtKB:  O70632
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupO70632
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 1 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on 308

Download Ideal Coordinates CCD File 
E [auth A](3S,5S,7S)-tricyclo[,7~]decan-1-amine
C10 H17 N
Experimental Data & Validation

Experimental Data

  • Conformers Calculated: 
  • Conformers Submitted: 
  • Selection Criteria: structures with the least restraint violations 

Structure Validation

View Full Validation Report

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2008-11-18
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2021-10-20
    Changes: Data collection, Database references, Derived calculations