title: Comparison of the major structural core proteins of tick-borne and Culicoides-borne orbiviruses.
abstract: Comparison of sequence data for Broadhaven (BRD) virus, a tick-borne orbivirus, and bluetongue virus (BTV), the type species of the genus, indicated that RNA segments 2 and 7 of BRD virus encode the two structural core proteins, VP2 and VP7, respectively. Segment 2 is 2792 nucleotides in length with a coding capacity for a protein (VP2) of 908 amino acids and a net charge of +8.5 at neutral pH. Segment 7 is 1174 nucleotides in length with a coding capacity for a protein (VP7) of 356 amino acids and a net charge of +11.5 at neutral pH. Comparison of the two sequences with BTV serotype 10 revealed amino acid identity of 35% between the product of segment 2 and BTV VP3, and 21% between the product of segment 7 and BTV VP7. The core proteins therefore show evidence of significant evolutionary divergence compared with that shown between different insect-borne orbiviruses. In particular, the amino terminus of BRD virus VP7 differed markedly from the equivalent region in VP7 of BTV and African horse sickness virus. This region is thought to interact with the outer capsid layer of insect-borne orbiviruses.
authors.affiliation: NERC Institute of Virology and Environmental Microbiology, Oxford, U.K.
authors.forename: S R
authors.initials: SR
authors.lastname: Moss
authors.forename: L D
authors.initials: LD
authors.lastname: Jones
authors.forename: P A
authors.initials: PA
authors.lastname: Nuttall
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000956:Antigens, Viral; D001483:Base Sequence; D002213:Capsid / Q000235:genetics; D036022:Capsid Proteins; D002478:Cells, Cultured; D002519:Ceratopogonidae; D005814:Genes, Viral / Q000235:genetics*; D007303:Insect Vectors; D008969:Molecular Sequence Data; D018163:Orbivirus / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013987:Ticks; D014758:Viral Core Proteins / Q000235:genetics*; D015678:Viral Structural Proteins / Q000235:genetics*
chemical_list: D000956:Antigens, Viral; D036022:Capsid Proteins; C442519:VP2 protein, African horse sickness virus; C442520:VP2 protein, Bluetongue virus; C050779:VP7 protein, Rotavirus; D014758:Viral Core Proteins; D015678:Viral Structural Proteins