Unité de Virologie Structurale


    Our initial studies of the 3D structure of the flaviviruses and of alphaviruses introduced the concept of class II viruses. These enveloped viruses have an icosahedrally symmetrical glycoprotein shell completely covering the viral membrane. The shell is sensitive to the environmental pH and/or to other signals encountered upon binding to the host cell. Shell dissociation allows the exposure of the fusion peptide, which is normally buried at oligomeric lateral contacts between envelope proteins at the particle surface. Exposure of the fusion peptide and its insertion into the target membrane, concomitant with the formation of homotrimers of the membrane fusion protein, leads to fusion of the viral and target membrane, allowing the release of the viral genome into the cytoplasm of the target cell.

    The only structural studies available within this class II concern alpha-, flavi- and rubiviridae viruses, but there are many other important and/or emerging pathogens belonging to this class, for which no structural information is yet available. These are the hepatitis C virus (HCV), the pestiviruses, the yellow fever virus, the bunyaviruses. We have developed efficient production and purification procedures to obtain recombinant envelope proteins from these viral pathogens.

Keywords : crystallography; virus; viral antigen; icosaedral particle; envelope membrane protein; viral enzyme; ribonucleoprotein; alphavirus; flavivirus; arbovirus.

  Chikungunya virus           Dengue virus            Picobirnavirus                 Herpesvirus               Arenavirus

Respiratory Syncytial virus     Hepatitis C virus               Pestivirus                     Rubella virus               C. elegans Eff-1