The ectodomains but not the transmembrane domains of the fusion proteins of subtypes A and B avian pneumovirus are conserved to a similar extent as those of human respiratory syncytial virus.
The fusion glycoprotein (F(B)) gene of five strains of the B subtype of avian pneumovirus (APV; turkey rhinotracheitis virus) has been sequenced. The length of the F(B) protein was 538 amino acids, identical to that of the F protein of subtype A virus, with which it had 74% and 83% overall nucleotide and deduced amino acid identities, respectively. The F(B) and F(A) ectodomains had 90% amino acid identity, very similar to the 91% identity between the ectodomains of the F proteins of subtype A and B human respiratory syncytial virus (HRSV). As with HRSV, the F2 polypeptide was less conserved (83% identity) than F1 (94%). In contrast to the ectodomain, the transmembrane and cytoplasmic domains of the two APV subtypes were much less conserved (30% and 48% identity, respectively) than those of HRSV (92% and 87%, respectively). Comparisons within all the genera of the Paramyxoviridae (Pneumovirus, Morbillivirus, Paramyxovirus and Rubullavirus) show that low amino acid identity between F protein transmembrane domains is a feature of different species of virus rather than of strain differences. This may indicate that the two subtypes of APV have evolved in different geographical regions and/or different avian species. This is the first report of an F gene sequence from a subtype B APV.
Naylor
C J
CJ
Institute for Animal Health, Compton Laboratory, Newbury, UK. Naylor@bbsrc.ac.uk
Britton
P
P
Cavanagh
D
D
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002462:Cell Membrane / Q000821:virology; D017124:Conserved Sequence; D004279:DNA, Viral; D005814:Genes, Viral; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics*; D015707:HN Protein; D006801:Humans; D008969:Molecular Sequence Data; D018111:Pneumovirus / Q000235:genetics*; D018113:Respiratory Syncytial Virus, Human / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014422:Turkeys / Q000821:virology; D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins / Q000737:chemistry / Q000235:genetics*; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics*
D004279:DNA, Viral; D006023:Glycoproteins; D015707:HN Protein; D014759:Viral Envelope Proteins; D014760:Viral Fusion Proteins; D014764:Viral Proteins; C116204:attachment protein G; C103938:glycoprotein F, turkey rhinotracheitis virus