Molecular cloning and characterization of W double-stranded RNA, a linear molecule present in Saccharomyces cerevisiae. Identification of its single-stranded RNA form as 20 S RNA.
Most strains of the yeast Saccharomyces cerevisiae harbor a double-stranded RNA (dsRNA) molecule, called W. We obtained W cDNA clones by random priming of denatured W dsRNA followed by reverse transcription. Sequence data of W shows that only one strand ((+)-strand) has coding capacity for a protein with 829 amino acids which spans almost the entire length of the molecule (2.5 kilobases). Within this protein we found a sequence pattern characteristic of RNA dependent RNA polymerases of (+)-strand and double-stranded RNA viruses. W has no homology with other dsRNAs found in S. cerevisiae, such as L-A, L-BC or M1. However, a (+)-strand-specific probe for W hybridized with 20-S RNA. Furthermore, W (+)-strands comigrated with 20 S RNA in strand separation gels. These results suggest that 20 S RNA is a (+)-single-stranded RNA form of W dsRNA itself or a closely related molecule.
Rodriguez-Cousiño
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N
Instituto de Microbiología Bioquímica Consejo Superior de Investigaciones Científicas/Universidad de Salamanca, Spain.
Esteban
L M
LM
Esteban
R
R
D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D003090:Coliphages / Q000235:genetics; D004247:DNA / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D005800:Genes, Fungal; D005814:Genes, Viral; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D012330:RNA, Double-Stranded / Q000235:genetics*; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014158:Transcription, Genetic
D012330:RNA, Double-Stranded; D004247:DNA