Analysis of the nucleoside triphosphatase, RNA triphosphatase, and unwinding activities of the helicase domain of dengue virus NS3 protein.
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.
Wang
Chun-Chung
CC
Institute of Molecular Biology, Academia Sinica, Nankang, 115 Taipei, Taiwan.
Huang
Zhi-Shun
ZS
Chiang
Pei-Ling
PL
Chen
Chien-Tsun
CT
Wu
Huey-Nan
HN
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
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