Packaging in a yeast double-stranded RNA virus.
The yeast virus ScV-L1 has only two genes, cap and pol, which encode the capsid polypeptide and the viral polymerase, respectively. The second gene is translated only as a cap-pol fusion protein. This fusion protein is responsible for recognition of a specific small stem and loop region of the viral plus strands, of 19 to 31 bases in length, ensuring packaging specificity. We have used a related virus, ScV-La, which has about 29% codon identity with ScV-L1 in the most conserved region of the pol gene, to map the region in pol that is responsible for packaging L1. Characterization of a number of chimeric viral proteins that recognize L1 but have the La capsid region delimits the region necessary for recognition of L1 to a 76- to 82-codon portion of pol. In addition, we show that overproduction of the La capsid polypeptide results in curing of the ScV-La virus, analogous to the production of plants resistant to RNA viruses by virtue of systemic production of viral coat protein.
Yao
W
W
Department of Biological Sciences, State University of New York, Buffalo 14260.
Muqtadir
K
K
Bruenn
J A
JA
D000595:Amino Acid Sequence; D002213:Capsid / Q000235:genetics / Q000378:metabolism*; D004274:DNA, Recombinant; D012321:DNA-Directed RNA Polymerases / Q000235:genetics / Q000378:metabolism*; D005814:Genes, Viral; D008969:Molecular Sequence Data; D009024:Morphogenesis; D017354:Point Mutation; D012328:RNA Viruses / Q000235:genetics / Q000648:ultrastructure*; D012330:RNA, Double-Stranded / Q000378:metabolism*; D012367:RNA, Viral / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D015678:Viral Structural Proteins / Q000235:genetics
D004274:DNA, Recombinant; D012330:RNA, Double-Stranded; D012367:RNA, Viral; D015678:Viral Structural Proteins; D012321:DNA-Directed RNA Polymerases