In vitro translation of cucumoviral satellites. II. CARNA 5 from cucumber mosaic virus strain S and SP6 transcripts of cloned (S)CARNA 5 cDNA produce electrophoretically comigrating protein products.

This report shows that (S)CARNA 5, the satellite of cucumber mosaic virus (CMV) strain S, directs the synthesis of two small proteins in a wheat germ cell-free translation system. The two proteins are produced by the translation of both (S)CARNA 5 purified from CMV virions and the (+) strand purified from double-stranded (S)CARNA 5. In addition, two protein products that comigrate electrophoretically with those above are produced when transcripts synthesized in vitro from full-length (S)CARNA 5 cDNA cloned in the plasmid pSP65 are substituted for (S)CARNA 5 in the translation system. The two proteins therefore must derive from a single (S)CARNA 5 sequence.