Reovirus lambda 1 protein: affinity for double-stranded nucleic acids by a small amino-terminal region of the protein independent from the zinc finger motif.
The reovirus lambda 1 protein, a major component of the inner capsid, has been shown to exhibit an affinity for dsRNA in a 'Northwestern' filter-binding assay. In the present study it was demonstrated that the protein can bind dsDNA as well as dsRNA. A bacterial expression system was used to study the protein region able to bind to nucleic acids. The amino-terminal 187 amino acids of lambda 1 were fused to the bacterial maltose-binding protein and shown to be sufficient for binding to nucleic acids. The putative zinc finger present on lambda 1 is not encompassed in this fragment of the protein. Site-directed mutagenesis also indicated that this zinc finger motif is unrelated to binding. In contrast, mutations introduced in a previously suggested nucleotide-binding motif almost completely prevented the binding. These data indicate that the amino-terminal end of lambda 1, encompassing its nucleotide-binding motif, is involved in the affinity of this protein for nucleic acids.
Lemay
G
G
Département de Microbiologie et Immunologie, Université de Montréal, Station Centre-ville, Québec, Canada.
Danis
C
C
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D002213:Capsid / Q000302:isolation & purification / Q000378:metabolism*; D036022:Capsid Proteins; D004247:DNA / Q000302:isolation & purification / Q000378:metabolism; D004268:DNA-Binding Proteins; D015151:Immunoblotting; D007739:L Cells; D012089:Mammalian orthoreovirus 3 / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D012330:RNA, Double-Stranded / Q000302:isolation & purification / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000378:metabolism; D016335:Zinc Fingers
D036022:Capsid Proteins; D004268:DNA-Binding Proteins; D012330:RNA, Double-Stranded; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C090196:lambda 1 protein, reovirus; D004247:DNA