title: Analysis of the nucleoside triphosphatase, RNA triphosphatase, and unwinding activities of the helicase domain of dengue virus NS3 protein.
abstract: The helicase domain of dengue virus NS3 protein (DENV NS3H) contains RNA-stimulated nucleoside triphosphatase (NTPase), ATPase/helicase, and RNA 5'-triphosphatase (RTPase) activities that are essential for viral RNA replication and capping. Here, we show that DENV NS3H unwinds 3'-tailed duplex with an RNA but not a DNA loading strand, and the helicase activity is poorly processive. The substrate of the divalent cation-dependent RTPase activity is not restricted to viral RNA 5'-terminus, a protruding 5'-terminus made the RNA 5'-triphosphate readily accessible to DENV NS3H. DENV NS3H preferentially binds RNA to DNA, and the functional interaction with RNA is sensitive to ionic strength.
authors.affiliation: Institute of Molecular Biology, Academia Sinica, Nankang, 115 Taipei, Taiwan.
authors.forename: Chun-Chung
authors.initials: CC
authors.lastname: Wang
authors.forename: Zhi-Shun
authors.initials: ZS
authors.lastname: Huang
authors.forename: Pei-Ling
authors.initials: PL
authors.lastname: Chiang
authors.forename: Chien-Tsun
authors.initials: CT
authors.lastname: Chen
authors.forename: Huey-Nan
authors.initials: HN
authors.lastname: Wu
mesh_terms: D017766:Acid Anhydride Hydrolases / Q000235:genetics / Q000378:metabolism*; D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D003001:Cloning, Molecular; D003716:Dengue Virus / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D006639:Histidine / Q000737:chemistry; D008969:Molecular Sequence Data; D009154:Mutation; D043583:Nucleoside-Triphosphatase / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism; D012697:Serine Endopeptidases / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000378:metabolism; D012703:Serotyping; D017361:Viral Nonstructural Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D017766:Acid Anhydride Hydrolases; D006639:Histidine; D043583:Nucleoside-Triphosphatase; D020365:RNA Helicases; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; D017361:Viral Nonstructural Proteins; C060028:NS3 protein, flavivirus; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases; C023090:RNA triphosphatase