Localization of genes for the double-stranded RNA killer virus of yeast.

The M double-stranded RNA (ds RNA) genome segment of the cytoplasmically inherited killer virus of yeast codes for two polypeptides when denatured and translated in vitro: a previously known 32,000-dalton peptide and a newly discovered 19,000-dalton peptide (NaDodSO4/polyacrylamide gel electrophoresis). An internal 190-base-pair region of the ds RNA is selectively degraded by S1 nuclease treatment at 65 degrees C, resulting in two ds RNA fragments which contain the termini of the original ds RNA. The larger fragment codes for the 32,000-dalton polypeptide and the smaller fragment codes for the 19,000-dalton polypeptide. Thus, the two gene products of M are encoded by distinct regions of this ds RNA.