C-terminal domain of the hepatitis C virus NS3 protein contains an RNA helicase activity

Biochem Biophys Res Commun. 1995 Oct 4;215(1):160-6. doi: 10.1006/bbrc.1995.2447.


The Hepatitis C Virus (HCV) NS3 protein contains amino acid motifs of a serine proteinase, a nucleotide triphosphatase (NTPase), and an RNA helicase based on amino acid sequence analysis. Proteinase and NTPase activities of the HCV NS3 protein were reported by several investigators. Here, we show that the recombinant HCV NS3 protein purified from a T7 promoter and His-tag expression system possesses an RNA helicase activity. The recombinant HCV NS3 protein consists of 466 amino acids from the carboxy terminal of a HCV NS3 open reading frame and 25 additional residues from the vector. The recombinant HCV NS3 protein was purified by metal-binding chromatography. The helicase activity requires ATP and divalent cations such as Mg2+ and Mn2+. The helicase activity was abolished by monoclonal antibody specific to the HCV NS3 protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / pharmacology
  • Base Sequence
  • Cations, Divalent
  • Chromatography, Affinity
  • Magnesium / pharmacology
  • Manganese / pharmacology
  • Molecular Sequence Data
  • RNA Helicases
  • RNA Nucleotidyltransferases / metabolism*
  • Recombinant Proteins / metabolism
  • Viral Nonstructural Proteins / chemistry*
  • Viral Nonstructural Proteins / genetics
  • Viral Nonstructural Proteins / metabolism*


  • Cations, Divalent
  • NS3 protein, hepatitis C virus
  • Recombinant Proteins
  • Viral Nonstructural Proteins
  • Manganese
  • Adenosine Triphosphate
  • RNA Nucleotidyltransferases
  • RNA Helicases
  • Magnesium