Oligomerization and cooperative RNA synthesis activity of hepatitis C virus RNA-dependent RNA polymerase.
Article Details
- CitationCopy to clipboard
Wang QM, Hockman MA, Staschke K, Johnson RB, Case KA, Lu J, Parsons S, Zhang F, Rathnachalam R, Kirkegaard K, Colacino JM
Oligomerization and cooperative RNA synthesis activity of hepatitis C virus RNA-dependent RNA polymerase.
J Virol. 2002 Apr;76(8):3865-72.
- PubMed ID
- 11907226 [ View in PubMed]
- Abstract
The NS5B RNA-dependent RNA polymerase encoded by hepatitis C virus (HCV) plays a key role in viral replication. Reported here is evidence that HCV NS5B polymerase acts as a functional oligomer. Oligomerization of HCV NS5B protein was demonstrated by gel filtration, chemical cross-linking, temperature sensitivity, and yeast cell two-hybrid analysis. Mutagenesis studies showed that the C-terminal hydrophobic region of the protein was not essential for its oligomerization. Importantly, HCV NS5B polymerase exhibited cooperative RNA synthesis activity with a dissociation constant, K(d), of approximately 22 nM, suggesting a role for the polymerase-polymerase interaction in the regulation of HCV replicase activity. Further functional evidence includes the inhibition of the wild-type NS5B polymerase activity by a catalytically inactive form of NS5B. Finally, the X-ray crystal structure of HCV NS5B polymerase was solved at 2.9 A. Two extensive interfaces have been identified from the packing of the NS5B molecules in the crystal lattice, suggesting a higher-order structure that is consistent with the biochemical data.