title: Purified recombinant bluetongue virus VP1 exhibits RNA replicase activity.
abstract: The polymerase protein of all known double-stranded RNA (dsRNA) viruses is located within a complex subviral core particle that is responsible for transcription of the viral genome. For members of the family Reoviridae, this particle allows messenger sense RNA synthesis while sequestering the viral genome away from cellular dsRNA surveillance systems during infection of eukaryotic cells. The core particle of bluetongue virus (BTV) consists of the major structural proteins VP3 and VP7 and the minor enzymatic proteins VP1 (polymerase), VP4 (capping enzyme), and VP6 (helicase). In this report we have characterized fully processive dsRNA synthesis by VP1 from a viral plus-strand RNA template in the absence of the other proteins of the BTV core. This replicase activity consists of de novo initiation of synthesis, followed by elongation of the minus strand. Purified VP1 exhibits little sequence specificity for BTV plus-strand template, suggesting that the choice of viral over nonviral RNA template comes from its association with other proteins within the viral core.
authors.affiliation: Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Boyce
authors.forename: Josa
authors.initials: J
authors.lastname: Wehrfritz
authors.forename: Rob
authors.initials: R
authors.lastname: Noad
authors.forename: Polly
authors.initials: P
authors.lastname: Roy
mesh_terms: D000818:Animals; D001483:Base Sequence; D001820:Bluetongue virus / Q000201:enzymology* / Q000235:genetics; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D066298:In Vitro Techniques; D012313:RNA / Q000235:genetics / Q000378:metabolism; D012330:RNA, Double-Stranded / Q000096:biosynthesis / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D018411:Spodoptera; D013379:Substrate Specificity
chemical_list: D036022:Capsid Proteins; D012330:RNA, Double-Stranded; D012367:RNA, Viral; D011994:Recombinant Proteins; D012313:RNA; D012324:RNA-Dependent RNA Polymerase