Polymerase-defective mutant of the Bryan high-titer strain of Rous sarcoma virus.
A mutant of the Bryan high-titer strain of Rous sarcoma virus defective in reverse transcriptase is known as type alpha (BH-RSV alpha). BH-RSV alpha virion particles do not contain any polymerase-related proteins but they direct the synthesis of a normal sized Pr180 gag-pol polyprotein precursor in infected cells. Using a bioassay for polymerase gene function that is based on the requirement of viral replication for transformation of transfected chicken cells, we have localized the defect to the 2.5 kb EcoRI-KpnI DNA fragment containing more than 90% of the polymerase gene by comparison with the corresponding DNA fragment from the wild-type polymerase-positive BH-RSV, called type beta. In vitro recombination experiments with the polymerase gene of Schmidt-Ruppin RSV allowed us to map the defect to the 0.86 kb XbaI-BglII DNA fragment of the BH-RSV alpha polymerase. DNA sequence analysis of the entire polymerase gene of BH-RSV alpha and beta has revealed one point mutation that maps within that XbaI-BglII fragment and substitutes leucine in BH-RSV alpha for glutamine in the wild-type BH-RSV beta.
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Sudol
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Lerner
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Hanafusa
D001358:Avian Sarcoma Viruses / Q000201:enzymology / Q000235:genetics*; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004279:DNA, Viral / Q000235:genetics; D015683:Gene Products, gag; D005796:Genes; D005814:Genes, Viral; D009154:Mutation; D012194:RNA-Directed DNA Polymerase / Q000172:deficiency / Q000235:genetics*; D012191:Retroviridae Proteins / Q000235:genetics; D014162:Transfection; D014779:Virus Replication
D004279:DNA, Viral; D015683:Gene Products, gag; D012191:Retroviridae Proteins; D012194:RNA-Directed DNA Polymerase