Influenza virus genome: finally discovered in its coat

To fight the virus that causes influenza, one of the avenues being explored by scientists is the development of drugs capable of destabilising its genome, made up of eight RNA1  molecules. But the challenge is daunting: each RNA molecule is tightly bound to an assembly of proteins which creates a double helix, forming a protective coat that is difficult to manipulate.

For the first time, however, the structure of this protective mantle and its interactions with the virus' RNA have been described on an atomic scale by scientists from the CNRS2  and l’Université Grenoble Alpes – a result that has been awaited by the scientific community for almost forty years. The research team has also revealed the precise positioning of the RNA molecules in their protective coat, and the interactions between the two helix strands.

The results have just been published in the journal Nucleic Acids Research, and were obtained using biochemical approaches and state-of-the-art cryo-electron microscopy provided by the Integrated Structural Biology, Grenoble (CEA/CNRS/European Molecular Biology Laboratory/Université Grenoble Alpes). 

This breakthrough paves the way for the design of new drug molecules capable of binding to the protein coat, weakening viral RNA and inhibiting replication of the influenza virus, whose epidemics affect between 2 and 6 million people in France every winter, and cause around 10,000 deaths in susceptible individuals3 .

• 1 their genetic material consists of RNA. These viruses use the machinery of the cells they infect not only to replicate their RNA but also to decode it. The viral molecules thus produced then rearrange to form new copies of the virus, which go on to infect new cells.
• 2Working at l’Institut de biologie structurale (CEA/CNRS/Université Grenoble Alpes)
• 3 Institut Pasteur