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.
Ribas
J C
JC
Section on Genetics of Simple Eukaryotes, NIDDK, National Institutes of Health, Bethesda, Maryland 20892.
Fujimura
T
T
Wickner
R B
RB
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