Crystal structure of the NS3 protease-helicase from dengue virus
- 31 December 2007
- journal article
- research article
- Published by American Society for Microbiology in Journal of Virology
- Vol. 82 (1), 173-183
- https://doi.org/10.1128/JVI.01788-07
Abstract
Several flaviviruses are important human pathogens, including dengue virus, a disease against which neither a vaccine nor specific antiviral therapies currently exist. During infection, the flavivirus RNA genome is translated into a polyprotein, which is cleaved into several components. Nonstructural protein 3 (NS3) carries out enzymatic reactions essential for viral replication, including proteolysis of the polyprotein through its serine protease N-terminal domain, with a segment of 40 residues from the NS2B protein acting as a cofactor. The ATPase/helicase domain is located at the C terminus of NS3. Atomic structures are available for these domains separately, but a molecular view of the full-length flavivirus NS3 polypeptide is still lacking. We report a crystallographic structure of a complete NS3 molecule fused to 18 residues of the NS2B cofactor at a resolution of 3.15 angstrom. The relative orientation between the protease and helicase domains is drastically different than the single-chain NS3-NS4A molecule from hepatitis C virus, which was caught in the act of cis cleavage at the NS3-NS4A junction. Here, the protease domain sits beneath the ATP binding site, giving the molecule an elongated shape. The domain arrangement found in the crystal structure fits nicely into an envelope determined ab initio using small-angle X-ray scattering experiments in solution, suggesting a stable molecular conformation. We propose that a basic patch located at the surface of the protease domain increases the affinity for nucleotides and could also participate in RNA binding, explaining the higher unwinding activity of the full-length enzyme compared to that of the isolated helicase domain.Keywords
This publication has 58 references indexed in Scilit:
- Crystal Structure and Activity of Kunjin Virus NS3 Helicase; Protease and Helicase Domain Assembly in the Full Length NS3 ProteinJournal of Molecular Biology, 2007
- Crystal Structure of the Dengue Virus RNA-Dependent RNA Polymerase Catalytic Domain at 1.85-Angstrom ResolutionJournal of Virology, 2007
- Structural evidence for regulation and specificity of flaviviral proteases and evolution of the Flaviviridae foldProtein Science, 2007
- A multi-step strategy to obtain crystals of the dengue virus RNA-dependent RNA polymerase that diffract to high resolutionActa Crystallographica Section F Structural Biology and Crystallization Communications, 2007
- Structure-Based Mutational Analysis of the NS3 Helicase from Dengue VirusJournal of Virology, 2006
- Protein production by auto-induction in high-density shaking culturesProtein Expression and Purification, 2005
- Coot: model-building tools for molecular graphicsActa Crystallographica Section D-Biological Crystallography, 2004
- The CCP4 suite: programs for protein crystallographyActa Crystallographica Section D-Biological Crystallography, 1994
- Determination of the regularization parameter in indirect-transform methods using perceptual criteriaJournal of Applied Crystallography, 1992
- FLAVIVIRUS GENOME ORGANIZATION, EXPRESSION, AND REPLICATIONAnnual Review of Microbiology, 1990