Genomic characterization of the unclassified bovine enteric virus Newbury agent-1 (Newbury1) endorses a new genus in the family Caliciviridae.
The pathogenic bovine enteric virus, Newbury agent-1 (Bo//Newbury1/1976/UK), first identified in 1976, was characterized as a possible calicivirus by morphology, buoyant density in CsCl and the presence of a single capsid protein but genomic sequence could not be obtained. In the present study, the complete genome sequence of Newbury1 was determined and classified Newbury1 in a new genus of the Caliciviridae. The Newbury1 genome, of 7454 nucleotides, had two predicted open reading frames (ORFs). ORF1 encoded the non-structural and contiguous capsid proteins. ORF2 encoded a basic protein characteristic of the family Caliciviridae. Compared to the 4 recognized Caliciviridae genera, Norovirus, Sapovirus, Lagovirus and Vesivirus, Newbury1 had less than 39% amino acid (47% nucleotide) identity in the complete 2C-helicase, 3C-protease, 3D-polymerase and capsid regions but had 89% to 98% amino acid (78% to 92% nucleotide) identity to the recently characterized NB virus in these regions. By phylogenetic analyses, Newbury1 and NB viruses formed a distinct clade independent of the 4 recognized genera. However, amino acid identities showed that Newbury1 and the NB virus were distinct polymerase types (90% amino acid identity), but their complete capsid proteins were almost identical (98% amino acid identity). Analyses of contemporary viruses showed that the two polymerase genotypes, Newbury1 and NB, were circulating in UK cattle and antibody to Newbury1-like viruses was common in cattle sera. The present study defined the existence of a new genus in the Caliciviridae that we propose be named Becovirus or Nabovirus to distinguish the new clade from bovine noroviruses.
Department of Pathology and Infectious Diseases, Royal Veterinary College, 4, Royal College Street, Camden, London NW1 0TU, UK. sloliver@stanford.edu
S L
SL
Oliver
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E
Asobayire
A M
AM
Dastjerdi
J C
JC
Bridger
D000595:Amino Acid Sequence; D000818:Animals; D002139:Caliciviridae / Q000145:classification* / Q000235:genetics* / Q000648:ultrastructure; D036022:Capsid Proteins / Q000235:genetics; D002417:Cattle; D002418:Cattle Diseases / Q000821:virology*; D004259:DNA-Directed DNA Polymerase / Q000235:genetics; D004751:Enteritis / Q000662:veterinary / Q000821:virology; D016679:Genome, Viral; D023281:Genomics; D008969:Molecular Sequence Data; D010802:Phylogeny
D036022:Capsid Proteins; D004259:DNA-Directed DNA Polymerase