title: The RNA-unwinding activity of hepatitis C virus non-structural protein 3 (NS3) is positively modulated by its protease domain.
abstract: The nonstructural protein 3 (NS3) of hepatitis C virus contains a protease domain at its amino terminus and RNA helicase domain at its carboxyl terminus. To identify optimal NS3 protein for developing screening assays, we expressed full-length NS3 protease/helicase and helicase domains from both HCV type 1a (H77 strain) and 1b (Con1 strain), using either E. coli or baculovirus expression systems. Our studies showed that the full-length NS3 proteins, either with or without the presence of the NS4A domain, from either strains were at least 10-fold more efficient than the corresponding helicase domains in unwinding partial duplex RNA substrates. These findings provide a rationale for the use of full-length NS3 in high throughput screening assays to identify potent small molecule inhibitors of this important target of HCV.
authors.affiliation: Gene Expression and Protein Biochemistry, GlaxoSmithKline, King of Prussia, PA 19406, USA.
authors.forename: Baohua
authors.initials: B
authors.lastname: Gu
authors.forename: Cynthia M
authors.initials: CM
authors.lastname: Pruss
authors.forename: Adam T
authors.initials: AT
authors.lastname: Gates
authors.forename: Sanjay S
authors.initials: SS
authors.lastname: Khandekar
mesh_terms: D016367:Baculoviridae / Q000235:genetics; D002850:Chromatography, Gel; D004926:Escherichia coli / Q000235:genetics; D017434:Protein Structure, Tertiary; D020365:RNA Helicases / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis; D012697:Serine Endopeptidases / Q000378:metabolism*; D017361:Viral Nonstructural Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases
chemical_list: D020365:RNA Helicases; D011994:Recombinant Proteins; D012697:Serine Endopeptidases; D017361:Viral Nonstructural Proteins; C084422:NS3 protein, hepatitis C virus; D043583:Nucleoside-Triphosphatase; D053487:DEAD-box RNA Helicases; D000085242:Viral Proteases