title: Comparative mechanistic studies of de novo RNA synthesis by flavivirus RNA-dependent RNA polymerases.
abstract: Flavivirus protein NS5 harbors the RNA-dependent RNA polymerase (RdRp) activity. In contrast to the RdRps of hepaci- and pestiviruses, which belong to the same family of Flaviviridae, NS5 carries two activities, a methyltransferase (MTase) and a RdRp. RdRp domains of Dengue virus (DV) and West Nile virus (WNV) NS5 were purified in high yield relative to full-length NS5 and showed full RdRp activity. Steady-state enzymatic parameters were determined on homopolymeric template poly(rC). The presence of the MTase domain does not affect the RdRp activity. Flavivirus RdRp domains might bear more than one GTP binding site displaying positive cooperativity. The kinetics of RNA synthesis by four Flaviviridae RdRps were compared. In comparison to Hepatitis C RdRp, DV and WNV as well as Bovine Viral Diarrhea virus RdRps show less rate limitation by early steps of short-product formation. This suggests that they display a higher conformational flexibility upon the transition from initiation to elongation.
authors.affiliation: Centre National de la Recherche Scientifique and Universités d'Aix-Marseille I et II, UMR 6098, Architecture et Fonction des Macromolécules Biologiques, AFMB-CNRS-ESIL, 13288 Marseille Cedex 9, France.
authors.forename: Barbara
authors.initials: B
authors.lastname: Selisko
authors.forename: Hélène
authors.initials: H
authors.lastname: Dutartre
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Guillemot
authors.forename: Claire
authors.initials: C
authors.lastname: Debarnot
authors.forename: Delphine
authors.initials: D
authors.lastname: Benarroch
authors.forename: Alexander
authors.initials: A
authors.lastname: Khromykh
authors.forename: Philippe
authors.initials: P
authors.lastname: Desprès
authors.forename: Marie-Pierre
authors.initials: MP
authors.lastname: Egloff
authors.forename: Bruno
authors.initials: B
authors.lastname: Canard
mesh_terms: D000595:Amino Acid Sequence; D003716:Dengue Virus / Q000201:enzymology; D018067:Flaviviridae / Q000201:enzymology*; D015967:Gene Expression Regulation, Viral; D008969:Molecular Sequence Data; D012367:RNA, Viral / Q000096:biosynthesis*; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014902:West Nile virus / Q000201:enzymology
chemical_list: D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase