Atomic structures of dengue virus are giving new hope for creation of a vaccine
The Dengue Virus Genome
A Deadly Switch
The Hunt for a Dengue Vaccine
For information on dengue fever, see http://www.niaid.nih.gov/topics/denguefever/
Building New Viruses
Exploring the Structure
Dengue Virus with Antibodies (PDB entry 2r6p)
Cryoelectron microscopy has been used to study many aspects of the life cycle of the dengue virus. In these structures, a low resolution image of virus, not quite detailed enough to see atoms, is obtained by the electron microscope, and then atomic structures of the individual pieces are fit into the image to generate the final model. The one shown here, from PDB entry 2r6p , shows the envelope protein on the surface of the virus (in white) with many antibody Fab fragments (in blue) bound to the viral proteins. By looking carefully at this structure, researchers have discovered that the antibodies distort the arrangement of the envelope proteins, blocking their normal action in infection. Other dengue virus structures in the PDB include immature forms of the virus (for instance, in PDB entry 1n6g ) and structures that include the membrane-spanning portions of the viral coat (PDB entry 1p58 ). To take a close-up look at the interaction of these antibodies with the virus, click on the image for an interactive JSmol.
Topics for Further Discussion
- The dengue virus is surrounded by 180 copies of the envelope protein. Many other viruses are surrounded by capsids composed of many identical proteins, and these often appear in multiples of 60, such as 180, 240 or 420 copies. What is significant about these numbers? Can you find examples of each in the PDB?
- Dengue virus is a member of a family of flaviviruses that are spread by ticks and mosquitoes. Other examples include yellow fever virus and West Nile virus. Looking at the structures in the PDB, can you see similarities in the proteins made by these viruses?
- Dengue virus replicates in the cytoplasm of infected cells, without entering the nucleus. Can you think of any problems this might cause, and how the dengue virus solves them with its ten viral proteins?
July 2008, David Goodselldoi:10.2210/rcsb_pdb/mom_2008_7