Structural basis for receptor specificity of influenza B virus hemagglutinin

Proc Natl Acad Sci U S A. 2007 Oct 23;104(43):16874-9. doi: 10.1073/pnas.0708363104. Epub 2007 Oct 17.


Receptor-binding specificity of HA, the major surface glycoprotein of influenza virus, primarily determines the host ranges that the virus can infect. Influenza type B virus almost exclusively infects humans and contributes to the annual "flu" sickness. Here we report the structures of influenza B virus HA in complex with human and avian receptor analogs, respectively. These structures provide a structural basis for the different receptor-binding properties of influenza A and B virus HA molecules and for the ability of influenza B virus HA to distinguish human and avian receptors. The structure of influenza B virus HA with avian receptor analog also reveals how mutations in the region of residues 194 to 196, which are frequently observed in egg-adapted and naturally occurring variants, directly affect the receptor binding of the resultant virus strains. Furthermore, these structures of influenza B virus HA are compared with known structures of influenza A virus HAs, which suggests the role of the residue at 222 as a key and likely a universal determinant for the different binding modes of human receptor analogs by different HA molecules.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Binding Sites
  • Birds
  • Crystallography, X-Ray
  • Hemagglutinins / chemistry*
  • Hemagglutinins / metabolism*
  • Humans
  • Influenza B virus / chemistry*
  • Molecular Sequence Data
  • Protein Binding
  • Protein Structure, Secondary
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / metabolism*
  • Species Specificity
  • Structure-Activity Relationship


  • Hemagglutinins
  • Receptors, Cell Surface

Associated data

  • PDB/2RFT
  • PDB/2RFU