Analysis of the nucleoside triphosphatase, RNA triphosphatase, and unwinding activities of the helicase domain of dengue virus NS3 protein

FEBS Lett. 2009 Feb 18;583(4):691-6. doi: 10.1016/j.febslet.2009.01.008. Epub 2009 Jan 21.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Anhydride Hydrolases / genetics
  • Acid Anhydride Hydrolases / metabolism*
  • Amino Acid Motifs
  • Amino Acid Sequence
  • Cloning, Molecular
  • Dengue Virus / genetics
  • Dengue Virus / metabolism*
  • Escherichia coli / genetics
  • Histidine / chemistry
  • Molecular Sequence Data
  • Mutation
  • Nucleoside-Triphosphatase / genetics
  • Nucleoside-Triphosphatase / metabolism*
  • Protein Structure, Tertiary
  • RNA Helicases / chemistry
  • RNA Helicases / classification
  • RNA Helicases / genetics
  • RNA Helicases / metabolism
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Serine Endopeptidases / chemistry
  • Serine Endopeptidases / classification
  • Serine Endopeptidases / genetics
  • Serine Endopeptidases / metabolism
  • Serotyping
  • Viral Nonstructural Proteins / chemistry*
  • Viral Nonstructural Proteins / classification
  • Viral Nonstructural Proteins / genetics
  • Viral Nonstructural Proteins / metabolism*

Substances

  • NS3 protein, flavivirus
  • Recombinant Proteins
  • Viral Nonstructural Proteins
  • Histidine
  • Serine Endopeptidases
  • Acid Anhydride Hydrolases
  • RNA triphosphatase
  • Nucleoside-Triphosphatase
  • RNA Helicases