Analysis of a translational enhancer present within the 5'-terminal sequence of the genomic RNA of potato virus S.

When present as a transcript leader the 5' untranslated sequence from the potato virus S genomic RNA molecule enhances translation of a downstream open reading frame both in vitro and in vivo. Translational enhancement was 30-fold in rabbit reticulocyte lysate and 15 fold in wheat germ above translation from a transcript with a synthetic leader. Transient expression experiments using tobacco protoplasts and particle bombardment of leaf tissue resulted in enhancement of fourteen and five-fold, respectively, above translation with a synthetic leader. In stably transformed plants the PVS 5'UTR enhanced translation yield ca. 5-fold compared with a synthetic 5'UTR.