Packaging Signal-mediated Assembly:How Viruses Outsmart Their Hosts

The importance of the genetic code in virology is universally acknowledged. However, it is less known that viral genomes can harbour a second code, embedded within the genetic code, that orchestrates the efficient assembly and genome packaging in many viral systems. Since its discovery in a bacterial virus, the molecular details and function of this mechanism have been characterised in a broad range of viral families, including major human pathogens. This Perspective article reports on the hallmarks of this "assembly/packaging code", the journey of its discovery, and the enticing opportunities it brings both in antiviral therapy and in virus nanotechnology.