RNA-Stimulated ATPase and RNA Helicase Activities and RNA Binding Domain of Hepatitis G Virus Nonstructural Protein 3
| Autor: | Jang H. Han, Yousang Gwack, Inyoung Song, Hyouna Yoo, Joonho Choe |
|---|---|
| Rok vydání: | 1999 |
| Předmět: |
viruses
Immunology Replication RNA-dependent RNA polymerase Viral Nonstructural Proteins Biology Microbiology Transcription (biology) Virology Escherichia coli Animals Humans Adenosine Triphosphatases Binding Sites Flaviviridae RNA-Binding Proteins virus diseases RNA biochemical phenomena metabolism and nutrition Non-coding RNA RNA Helicase A Molecular biology digestive system diseases Biochemistry RNA editing Insect Science Primase Degradosome RNA Helicases |
| Zdroj: | Journal of Virology. 73:2909-2915 |
| ISSN: | 1098-5514 0022-538X |
| DOI: | 10.1128/jvi.73.4.2909-2915.1999 |
| Popis: | Hepatitis G virus (HGV) nonstructural protein 3 (NS3) contains amino acid sequence motifs typical of ATPase and RNA helicase proteins. In order to examine the RNA helicase activity of the HGV NS3 protein, the NS3 region (amino acids 904 to 1580) was fused with maltose-binding protein (MBP), and the fusion protein was expressed in Escherichia coli and purified with amylose resin and anion-exchange chromatography. The purified MBP-HGV/NS3 protein possessed RNA-stimulated ATPase and RNA helicase activities. Characterization of the ATPase and RNA helicase activities of MBP-HGV/NS3 showed that the optimal reaction conditions were similar to those of other Flaviviridae viral NS3 proteins. However, the kinetic analysis of NTPase activity showed that the MBP-HGV/NS3 protein had several unique properties compared to the other Flaviviridae NS3 proteins. The HGV NS3 helicase unwinds RNA-RNA duplexes in a 3′-to-5′ direction and can unwind RNA-DNA heteroduplexes and DNA-DNA duplexes as well. In a gel retardation assay, the MBP-HGV/NS3 helicase bound to RNA, RNA/DNA, and DNA duplexes with 5′ and 3′ overhangs but not to blunt-ended RNA duplexes. We also found that the conserved motif VI was important for RNA binding. Further deletion mapping showed that the RNA binding domain was located between residues 1383 and 1395, QRRGRTGRGRSGR. Our data showed that the MBP-HCV/NS3 protein also contains the RNA binding domain in the similar domain. |
| Databáze: | OpenAIRE |
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