Rous sarcoma virus nucleic acid-binding protein p12 is necessary for viral 70S RNA dimer formation and packaging.
To study the function(s) of the Rous sarcoma virus nucleic acid-binding protein p12, we constructed mutants by using two restriction sites in the p12 proviral coding sequence of the Prague C strain to insert KpnI synthetic linkers. The two restriction sites are in the same reading frame, which allowed us to construct a deletion mutant lacking the two conserved Cys-His regions and a duplication mutant containing three intact Cys-His boxes. These mutant DNAs were transfected into chicken embryo fibroblasts, and the viral particles produced in a transient assay were characterized biochemically and for infectivity. Our results indicate that the Rous sarcoma virus nucleic acid-binding protein p12 is necessary for genomic RNA packaging but not for particle assembly and is implicated in the formation of a stable 70S dimeric RNA. Moreover, the fact that one mutant was apparently able to package normal 70S RNA but was not infectious suggests a role for p12 during the infection process.
D000818:Animals; D001358:Avian Sarcoma Viruses / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D002642:Chick Embryo; D015683:Gene Products, gag; D005814:Genes, Viral; D005816:Genetic Complementation Test; D009154:Mutation; D012367:RNA, Viral / Q000032:analysis / Q000378:metabolism*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D012191:Retroviridae Proteins / Q000378:metabolism*; D014162:Transfection; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
D015683:Gene Products, gag; D012367:RNA, Viral; D012191:Retroviridae Proteins; D014764:Viral Proteins; D012194:RNA-Directed DNA Polymerase