• The avian influenza virus needs to mutate to cross the species barrier and to infect and replicate within mammalian cells. • The Cusack group from EMBL Grenoble has deciphered the structure of the avian influenza virus’s polymerase when it interacts with a human protein essential for the virus to replicate within the cell. • The structure of this replication complex, published in Nature Communications, provides important information about the mutations that avian influenza polym...
