Download MendeleyStructure of the Dengue Virus Helicase/Nucleoside Triphosphatase Catalytic Domain at a Resolution of 2.4 A.
Xu, T., Sampath, A., Chao, A., Wen, D., Nanao, M., Chene, P., Vasudevan, S.G., Lescar, J.(2005) J Virol 79: 10278
- PubMed: 16051821
- DOI: https://doi.org/10.1128/JVI.79.16.10278-10288.2005
- Primary Citation of Related Structures:
2BHR, 2BMF - PubMed Abstract:
Dengue fever is an important emerging public health concern, with several million viral infections occurring annually, for which no effective therapy currently exists. The NS3 protein from Dengue virus is a multifunctional protein of 69 kDa, endowed with protease, helicase, and nucleoside 5'-triphosphatase (NTPase) activities. Thus, NS3 plays an important role in viral replication and represents a very interesting target for the development of specific antiviral inhibitors. We present the structure of an enzymatically active fragment of the Dengue virus NTPase/helicase catalytic domain to 2.4 A resolution. The structure is composed of three domains, displays an asymmetric distribution of charges on its surface, and contains a tunnel large enough to accommodate single-stranded RNA. Its C-terminal domain adopts a new fold compared to the NS3 helicase of hepatitis C virus, which has interesting implications for the evolution of the Flaviviridae replication complex. A bound sulfate ion reveals residues involved in the metal-dependent NTPase catalytic mechanism. Comparison with the NS3 hepatitis C virus helicase complexed to single-stranded DNA would place the 3' single-stranded tail of a nucleic acid duplex in the tunnel that runs across the basic face of the protein. A possible model for the unwinding mechanism is proposed.
Organizational Affiliation:
School of Biological Sciences, Nanyang Technological University, 60, Nanyang Drive, Singapore 637551.
