title: RNA-dependent RNA polymerase consensus sequence of the L-A double-stranded RNA virus: definition of essential domains.
abstract: The L-A double-stranded RNA virus of Saccharomyces cerevisiae makes a gag-pol fusion protein by a -1 ribosomal frameshift. The pol amino acid sequence includes consensus patterns typical of the RNA-dependent RNA polymerases (EC 2.7.7.48) of (+) strand and double-stranded RNA viruses of animals and plants. We have carried out "alanine-scanning mutagenesis" of the region of L-A including the two most conserved polymerase motifs, SG...T...NT..N (. = any amino acid) and GDD. By constructing and analyzing 46 different mutations in and around the RNA polymerase consensus regions, we have precisely defined the extent of domains and specific residues essential for viral replication. Assuming that this highly conserved region has a common secondary structure among different viruses, we predict a largely beta-sheet structure.
authors.affiliation: Section on the Genetics of Simple Eukaryotes, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892.
authors.forename: J C
authors.initials: JC
authors.lastname: Ribas
authors.forename: R B
authors.initials: RB
authors.lastname: Wickner
mesh_terms: D000595:Amino Acid Sequence; D005822:Genetic Vectors; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D012328:RNA Viruses / Q000201:enzymology / Q000235:genetics*; D012330:RNA, Double-Stranded / Q000235:genetics; D012367:RNA, Viral / Q000235:genetics; D012324:RNA-Dependent RNA Polymerase / Q000235:genetics*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D012845:Sindbis Virus / Q000201:enzymology / Q000235:genetics
chemical_list: D012330:RNA, Double-Stranded; D012367:RNA, Viral; D012324:RNA-Dependent RNA Polymerase