Researchers from the University of Helsinki, Karolinska Institutet and the Max Planck Biochemistry Institute have solved the three-dimensional structure of the Uukuniemi virus, which might help in explaining the infection mechanism of bunyaviruses.
The Uukuniemi virus is the first bunyavirus whose structure researchers have been able to determine.
Bunyaviridae is a family of negative-stranded RNA viruses. Though generally found in arthropods or rodents, certain viruses in this family occasionally infect humans.
Human infections with certain Bunyaviruses, such as Crimean-Congo Hemorrhagic Fever virus, are associated with high levels of morbidity and mortality, consequently handling of these viruses must occur with a Biosafety level 4 laboratory.
Together with more detailed studies of the viral membrane proteins, knowledge of the Uukuniemi virus may provide a basis for development of drugs for treating bunyavirus diseases, such as hemorrhagic fever and encephalitis.
In the study, the researchers solved the three-dimensional structure of the virus particle, which is only 0.0001 mm in diameter, using electron tomography and computational methods.
The newly determined virus structure also serves as a model for the other bunyaviruses.
The analysis revealed that the viral membrane proteins protruding as spikes from the Uukuniemi virus surface changed their shape in an acidic environment.
This phenomenon is reminiscent of the mechanism whereby influenza and dengue viruses enter their host cells. The observation helps to explain how bunyaviruses infect their host cells.
The study is published in PNAS.