Similarity between the picornavirus VP3 capsid polypeptide and the Saccharomyces cerevisiae virus capsid polypeptide

We have compared the sequence of the capsid polypeptide of the Saccharomyces cerevisiae double-stranded RNA virus, ScV, with those of the picornaviruses. A central region of 245 amino acids in the ScV capsid polypeptide of 680 amino acids has significant similarity to the picornavirus VP3. This similarity is more extensive than that already noted for the alphavirus capsid polypeptide and the picornavirus VP3 (Fuller, S.D. and Argos, P, EMBO J. 6, 1099, 1987). Together with the similarity between the ScV RNA polymerase and the picornavirus RNA polymerases, this result implies an evolutionary relationship between a simple double-stranded RNA virus of fungi and the small plus strand RNA animal viruses.