title: Inhibition of RNA binding to hepatitis C virus RNA-dependent RNA polymerase: a new mechanism for antiviral intervention.
abstract: The hepatitis C virus (HCV) RNA-dependent RNA polymerase (RdRp) is a key target for antiviral intervention. The goal of this study was to identify the binding site and unravel the molecular mechanism by which natural flavonoids efficiently inhibit HCV RdRp. Screening identified the flavonol quercetagetin as the most potent inhibitor of HCV RdRp activity. Quercetagetin was found to inhibit RdRp through inhibition of RNA binding to the viral polymerase, a yet unknown antiviral mechanism. X-ray crystallographic structure analysis of the RdRp-quercetagetin complex identified quercetagetin's binding site at the entrance of the RNA template tunnel, confirming its original mode of action. This antiviral mechanism was associated with a high barrier to resistance in both site-directed mutagenesis and long-term selection experiments. In conclusion, we identified a new mechanism for non-nucleoside inhibition of HCV RdRp through inhibition of RNA binding to the enzyme, a mechanism associated with broad genotypic activity and a high barrier to resistance. Our results open the way to new antiviral approaches for HCV and other viruses that use an RdRp based on RNA binding inhibition, that could prove to be useful in human, animal or plant viral infections.
authors: Inserm U955, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France.
authors: Abdelhakim
authors: A
authors: Ahmed-Belkacem
authors: Centre de Biochimie Structurale, Inserm U1054, CNRS UMR5048, Universités Montpellier 1 et 2, 29 rue de Navacelles, 34090 Montpellier, France.
authors: Jean-François
authors: JF
authors: Guichou
authors: Inserm U955, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France.
authors: Rozenn
authors: R
authors: Brillet
authors: Inserm U955, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France.
authors: Nazim
authors: N
authors: Ahnou
authors: Inserm U955, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France.
authors: Eva
authors: E
authors: Hernandez
authors: Inserm U955, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France Department of Virology, Hôpital Paul Brousse, 12 avenue Paul Vaillant Couturier, 94800 Villejuif, France.
authors: Coralie
authors: C
authors: Pallier
authors: Inserm U955, Hôpital Henri Mondor, 51 avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France National Reference Center for Viral Hepatitis B, C, and Delta, Department of Virology, Hôpital Henri Mondor, Université Paris-Est, 51 avenue du Maréchal de Lattre de Tassigny, 94010 Créteil, France jean-michel.pawlotsky@hmn.aphp.fr.
authors: Jean-Michel
authors: JM
authors: Pawlotsky
mesh_terms: D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D002460:Cell Line; D002867:Chromones / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D024882:Drug Resistance, Viral; D047309:Flavones; D005419:Flavonoids / Q000737:chemistry / Q000494:pharmacology; D016174:Hepacivirus / Q000235:genetics / Q000502:physiology; D006801:Humans; D012313:RNA / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D017361:Viral Nonstructural Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000378:metabolism; D014779:Virus Replication / Q000187:drug effects
chemical_list: D000998:Antiviral Agents; D002867:Chromones; D047309:Flavones; D005419:Flavonoids; D017361:Viral Nonstructural Proteins; D012313:RNA; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase; C079163:quercetagetin