TBE: activation mechanism of flaviviruses identified

A collaboration between researchers at the Center for Virology of the Medical University of Vienna and the Pasteur Institute in Paris has provided unexpected insights into the atomic interactions of the tick-borne encephalitis (TBE) virus in infected cells. In particular, the researchers identified a new molecular switch that is used to control the processes of virus assembly, virus maturation and entry into new cells. Because of their close relationship and structural homology, the insights gained from the TBE virus model are valid for all flaviviruses, including several major mosquito-borne viruses (e.g. dengue, yellow fever, Zika, Japanese encephalitis and West Nile virus). The research results were recently published in "Nature Communications". In order to replicate in an infected cell, viruses must be assembled and released as stable particles. Conversely, when they enter cells that are to be newly infected, they have to disintegrate to release their genetic information. In enveloped viruses such as TBE virus, the control of these opposing processes is based on the ability of viral envelope proteins to change their structure and become activated at different stages of the virus life cycle. In the case of flaviviruses, these conformational switches are triggered by the varying pH in different cellular compartments. X-ray structural analysis of an envelope protein complex