Virus-like particles containing either L or M double-stranded ribonucleic acid (dsRNA) were isolated from a killer toxin-producing strains of Saccharomyces cerevisiae (K+ R+). At least 95% of M- and 87% of L-dsRNA were recovered in virus-like particle-containing fractions. The major capsid polypeptides (ScV-P1) of both L and M virus-like particles were shown to be identical, and 95% of the cellular ScV-P1 was found in the virus-like particle-containing fractions. Since L-dsRNA encodes ScV-P1, provision of this protein for encapsidation of M-dsRNA defines at least one functional relationship between these dsRNA genomes and associates the L-dsRNA with the killer character. If encapsidation of M-dsRNA is essential for its replication or expression, then L-dsRNA plays an essential role in maintenance or expression of the killer phenotype. The relationship between the L- and M-dsRNA genomes would be analogous to that between a helper and a defective virus. The presence of only minor quantities or uncomplexed dsRNA and ScV-P1 suggests that their production is stringently coupled.
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机译：含有L或M双链核糖核酸（DSRNA）的病毒样颗粒从杀毒素酿酒酵母（K + R +）的杀伤毒素产生菌株中分离出来。在含病毒样颗粒的级分中回收至少95％的M-和87％的L-DSRNA。 L和M类病毒样颗粒的主要胶囊多肽（SCV-P1）显示出相同，并且在含病毒样颗粒的级分中发现95％的细胞SCV-P1。由于L-DSRNA编码SCV-P1，因此提供该蛋白质的用于封装M-DSRNA，这些蛋白质定义了这些DSRNA基因组之间的至少一种功能关系，并将L-DSRNA与杀伤性质相关联。如果M-DSRNA的封装对于其复制或表达至关重要，则L-DSRNA在杀手表型的维护或表达中起重要作用。 L-和M-DSRNA基因组之间的关系类似于辅助者和缺陷病毒之间的关系。仅存在少量或未复制的DSRNA和SCV-P1表明其生产是严格耦合的。
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