De Novo Initiation of RNA Synthesis by Hepatitis C Virus Nonstructural Protein 5B Polymerase
| Autor: | Eric Ferrari, Weidong Zhong, Johnson Y. N. Lau, Zhi Hong, Annette S. Uss |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
viruses
Immunology Replication RNA-dependent RNA polymerase Hepacivirus Viral Nonstructural Proteins Biology Microbiology Substrate Specificity chemistry.chemical_compound Virology RNA polymerase Humans NS5B virus diseases RNA Templates Genetic RNA-Dependent RNA Polymerase Non-coding RNA Molecular biology digestive system diseases RNA silencing chemistry RNA editing Insect Science RNA Viral Small nuclear RNA |
| Zdroj: | Journal of Virology. 74:2017-2022 |
| ISSN: | 1098-5514 0022-538X |
| DOI: | 10.1128/jvi.74.4.2017-2022.2000 |
| Popis: | 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- 32 P]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. |
| Databáze: | OpenAIRE |
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