Essential RNA binding and packaging domains of the Gag-Pol fusion protein of the L-A double-stranded RNA virus of Saccharomyces cerevisiae.
The crucial process in the assembly of the L-A double-stranded RNA virus is the recognition of its (+) single-stranded RNA by the Gag-Pol protein. The Pol region of this protein has RNA binding activity and is necessary for RNA packaging. Here we show that there are actually two in vitro RNA-binding domains of Pol (residues 172-190 and 770-819), and both are necessary for viral propagation, (but not for particle assembly). Furthermore, the N-terminal RNA-binding domain is necessary for in vivo packaging of viral (+) single-stranded RNA. We precisely define the extent of the Pol packaging domain (residues 67-213), which includes the N-terminal RNA-binding domain. This suggests that the N-terminal RNA-binding domain is responsible for binding the genomic RNA in the process of packaging and that additional surrounding residues are responsible for the specificity of binding.
Section on Genetics of Simple Eukaryotes, NIDDK, National Institutes of Health, Bethesda, Maryland 20892.
J C
JC
Ribas
T
T
Fujimura
R B
RB
Wickner
D000595:Amino Acid Sequence; D001483:Base Sequence; D001665:Binding Sites; D016368:Frameshift Mutation; D015685:Fusion Proteins, gag-pol / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D016366:Open Reading Frames; D012328:RNA Viruses / Q000378:metabolism*; D012330:RNA, Double-Stranded / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D012367:RNA, Viral / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000821:virology*; D014158:Transcription, Genetic
D015685:Fusion Proteins, gag-pol; D012330:RNA, Double-Stranded; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D011994:Recombinant Proteins