The hemagglutinin structure of an avian H1N1 influenza A virus

Virology. 2009 Sep 15;392(1):73-81. doi: 10.1016/j.virol.2009.06.028. Epub 2009 Jul 22.


The interaction between hemagglutinin (HA) and receptors is a kernel in the study of evolution and host adaptation of H1N1 influenza A viruses. The notion that the avian HA is associated with preferential specificity for receptors with Siaalpha2,3Gal glycosidic linkage over those with Siaalpha2,6Gal linkage is not all consistent with the available data on H1N1 viruses. By x-ray crystallography, the HA structure of an avian H1N1 influenza A virus, as well as its complexes with the receptor analogs, was determined. The structures revealed no preferential binding of avian receptor analogs over that of the human analog, suggesting that the HA/receptor binding might not be as stringent as is commonly believed in determining the host receptor preference for some subtypes of influenza viruses, such as the H1N1 viruses. The structure also showed difference in glycosylation despite the preservation of related sequences, which may partly contribute to the difference between structures of human and avian origin.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Birds / virology
  • Carbohydrate Sequence
  • Crystallography, X-Ray
  • DNA Primers / genetics
  • Glycosylation
  • Hemagglutinin Glycoproteins, Influenza Virus / chemistry*
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Humans
  • In Vitro Techniques
  • Influenza A Virus, H1N1 Subtype / chemistry*
  • Influenza A Virus, H1N1 Subtype / genetics
  • Mammals
  • Models, Molecular
  • Molecular Sequence Data
  • Molecular Structure
  • Protein Structure, Quaternary
  • Receptors, Virus / chemistry
  • Sequence Homology, Amino Acid
  • Species Specificity
  • Static Electricity


  • DNA Primers
  • Hemagglutinin Glycoproteins, Influenza Virus
  • Receptors, Virus
  • hemagglutinin, avian influenza A virus