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.
Oliver
S L
SL
Department of Pathology and Infectious Diseases, Royal Veterinary College, 4, Royal College Street, Camden, London NW1 0TU, UK. sloliver@stanford.edu
Asobayire
E
E
Dastjerdi
A M
AM
Bridger
J C
JC
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