Prokaryotic and eukaryotic translational machineries respond differently to the frameshifting RNA signal from plant or animal virus.

Many mutational and structural analyses of the RNA signals propose a hypothesis that programmed frameshifting occurs by a specific interaction between ribosome and frameshifting signals comprised of a shifty site and a downstream RNA structure, in which the exact nature of the interaction has not yet been proven. To address this question, we analyzed the frameshifting sequence elements from animal or plant virus in yeast and Escherichia coli. Frameshifting efficiencies varied in yeast, but not in E. coli, depending on the specific conformation of mouse mammary tumor virus (MMTV) RNA pseudoknot. Similar changes in frameshifting efficiencies were observed in yeast, but not in E. coli, for the mutations in frameshifting sequence elements from cereal yellow dwarf virus serotype RPV (CYDV-RPV). The differential response of MMTV or CYDV-RPV frameshifting signal to prokaryotic and eukaryotic translational machineries implies that ribosome pausing alone is insufficient to mediate frameshifting, and additional events including specific interaction between ribosome and RNA structural element are required for efficient frameshifting. These results supports the hypothesis that frameshifting occurs by a specific interaction between ribosome and frameshifting signal.