UC San Diego

Ligand-responsive RNA mechanical switches represent a new class of simple and small switching modules which regulate viral translation initiation by adopting well-defined ligand-free and bound conformational states without undergoing large secondary structure rearrangements, distinguishing them from metabolite-sensing riboswitches. Initially discovered in the internal ribosome entry site (IRES) of hepatitis C virus (HCV), RNA switch motifs have now been discovered in the genomes of diverse other viruses. Although large variations are seen in sequence and local secondary structure of these switches, their function in viral translation initiation requiring recognition of identical cognate ligands is conserved. These simple ligand-responsive viral RNA switches may be the target for therapeutic intervention and may be incorporated as tunable building blocks for nanotechnology.