De Novo Initiation of RNA Synthesis by Hepatitis C Virus Nonstructural Protein 5B Polymerase
AUTOR(ES)
Zhong, Weidong
FONTE
American Society for Microbiology
RESUMO
RNA-dependent RNA polymerase (RdRp) encoded by positive-strand RNA viruses is critical to the replication of viral RNA genome. Like other positive-strand RNA viruses, replication of hepatitis C virus (HCV) RNA is mediated through a negative-strand intermediate, which is generated through copying the positive-strand genomic RNA. Although it has been demonstrated that HCV NS5B alone can direct RNA replication through a copy-back primer at the 3′ end, de novo initiation of RNA synthesis is likely to be the mode of RNA replication in infected cells. In this study, we demonstrate that a recombinant HCV NS5B protein has the ability to initiate de novo RNA synthesis in vitro. The NS5B used HCV 3′ X-tail RNA (98 nucleotides) as the template to synthesize an RNA product of monomer size, which can be labeled by [γ-32P]nucleoside triphosphate. The de novo initiation activity was further confirmed by using small synthetic RNAs ending with dideoxynucleotides at the 3′ termini. In addition, HCV NS5B preferred GTP as the initiation nucleotide. The optimal conditions for the de novo initiation activity have been determined. Identification and characterization of the de novo priming or initiation activity by HCV NS5B provides an opportunity to screen for inhibitors that specifically target the initiation step.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=111680Documentos Relacionados
- Template Requirements for De Novo RNA Synthesis by Hepatitis C Virus Nonstructural Protein 5B Polymerase on the Viral X RNA
- Template/Primer Requirements and Single Nucleotide Incorporation by Hepatitis C Virus Nonstructural Protein 5B Polymerase
- De Novo Initiation of RNA Synthesis by the RNA-Dependent RNA Polymerase (NS5B) of Hepatitis C Virus
- Identification and Characterization of an RNA-Dependent RNA Polymerase Activity within the Nonstructural Protein 5B Region of Bovine Viral Diarrhea Virus
- Mechanism of De Novo Initiation by the Hepatitis C Virus RNA-Dependent RNA Polymerase: Role of Divalent Metals