title: Sequence analysis of the equine H7 influenza virus haemagglutinin gene.
abstract: The nucleotide sequences of ten haemagglutinin genes of representative H7N7 equine influenza viruses isolated between 1956 and 1977 have been determined by primer extension sequencing. Their nucleotide and deduced amino acid sequences demonstrate a high degree of homology. These equine viruses can be divided into two distinct subgroups, the prototype-like, and a group comprising the early American isolates and the remaining equine viruses. The equine H7 haemagglutinins form a quite distinct group compared to H7 haemagglutinins isolated from other species. Each of these equine H7 haemagglutinins possess a tetrabasic amino acid cleavage site separating the HA1 and HA2 domains but, in addition, all ten contain a nine amino acid insertion prior to the tetrabasic sequence. The haemagglutinin glycoproteins of all ten viruses are capable of cleavage activation in virus infected primary chicken embryo fibroblast cells.
authors.affiliation: National Institute for Biological Standards and Control, Potters Bar, U.K.
authors.forename: C A
authors.initials: CA
authors.lastname: Gibson
authors.forename: R S
authors.initials: RS
authors.lastname: Daniels
authors.forename: J S
authors.initials: JS
authors.lastname: Oxford
authors.forename: J W
authors.initials: JW
authors.lastname: McCauley
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005814:Genes, Viral; D014644:Genetic Variation; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000235:genetics* / Q000302:isolation & purification; D006736:Horses; D009980:Influenza A virus / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000737:chemistry / Q000302:isolation & purification; D012689:Sequence Homology, Nucleic Acid; D014759:Viral Envelope Proteins / Q000235:genetics / Q000302:isolation & purification; D015678:Viral Structural Proteins / Q000235:genetics*
chemical_list: D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D012367:RNA, Viral; D014759:Viral Envelope Proteins; D015678:Viral Structural Proteins