title: Classical swine fever virus NS3 enhances RNA-dependent RNA polymerase activity by binding to NS5B.
abstract: NS3 of pestiviruses contains a protease domain and a RNA helicase/NTPase domain. Contradictory results have been reported regarding NS3 in RNA synthesis. To investigate the effect of NS3 on classical swine fever virus (CSFV) NS5B RNA-dependent RNA polymerase activity (RdRp) activity and NS3-NS5B interaction, RdRp reactions, GST-pull-down assays and co-immunoprecipitation analyses containing NS5B and either of NS3 protein and the different truncated NS3 mutants were performed, respectively. We found that NS3 stimulated NS5B RdRp activity in a dose-dependent manner by binding to NS5 through a NS3 protease domain. Furthermore, mapping important regions of the NS3 protease domain was carried out by deletion mutagenesis, associated with RdRp reactions, GST-pull-down assays and co-immunoprecipitation analyses. Results showed that stimulation of CSFV NS5B RdRp activity was obtained by NS3 binding to NS5B through a 31-amino acid fragment at the N-terminal end of NS3 protease domain, which mediated a specific NS3-NS5B interaction.
authors: Research Institute for Agricultural Microbiology, College of Life and Environment Sciences, Shanghai Normal University, Shanghai, 200234, China.
authors: Ping
authors: P
authors: Wang
authors: Yujing
authors: Y
authors: Wang
authors: Yu
authors: Y
authors: Zhao
authors: Zailing
authors: Z
authors: Zhu
authors: Jialin
authors: J
authors: Yu
authors: Lingzhu
authors: L
authors: Wan
authors: Jun
authors: J
authors: Chen
authors: Ming
authors: M
authors: Xiao
mesh_terms: D000818:Animals; D006691:Classical Swine Fever / Q000821:virology; D006692:Classical Swine Fever Virus / Q000737:chemistry / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D012324:RNA-Dependent RNA Polymerase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013552:Swine; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D014764:Viral Proteins; D012324:RNA-Dependent RNA Polymerase