title: Characterization of a Rous sarcoma virus mutant defective in packaging its own genomic RNA: biochemical properties of mutant TK15 and mutant-induced transformants.
abstract: The accompanying paper (S. Kawai and T. Koyama , J. Virol. 51:147-153, 1984) describes the isolation and biological properties of a mutant, TK15 , derived from a Rous sarcoma virus mutant, tsNY68 . The cis-acting defect of the mutant is analyzed biochemically in this paper. TK15 virions released from virus-producing 15c (+) cells were deficient in viral genomic 39S RNA, although comparable amounts of viral RNAs were transcribed in 15c (+) and tsNY68 -infected cells. Analysis of provirus DNA occurring in 15c (+) cells suggested that the mutant genome had a deletion of ca. 250 bases near the 5' end of the genome somewhere between the primer binding site and the 5' end of the gag-coding region. These findings indicate that at least part of the sequence lost in the TK15 genome is indispensable for packaging viral genomic RNA into virions. TK15 induces nonvirus -producing 15c (-) transformants at high frequency. Southern blot analysis of DNAs from those 15c (-) clone cells revealed that TK15 -derived proviruses contained various extents of internal deletions. Many 15c (-) clones had a provirus carrying only the src gene with long terminal repeat sequences at both ends. The mechanism for the segregation of 15c (-) cells is discussed.
mesh_terms: D001358:Avian Sarcoma Viruses / Q000235:genetics*; D002472:Cell Transformation, Viral; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D009154:Mutation; D012313:RNA / Q000032:analysis; D012342:RNA, Small Nuclear; D012367:RNA, Viral / Q000032:analysis*; D012194:RNA-Directed DNA Polymerase / Q000378:metabolism; D014158:Transcription, Genetic; D014771:Virion / Q000032:analysis
chemical_list: D012342:RNA, Small Nuclear; D012367:RNA, Viral; D012313:RNA; D012194:RNA-Directed DNA Polymerase