title: Molecular dissection of the reovirus lambda1 protein nucleic acids binding site.
abstract: A recent study has shown that the reovirus lambda1 protein can unwind double-stranded nucleic acid molecules, a process energetically coupled to the hydrolysis of nucleoside 5'-triphosphates. In the present study, it was demonstrated that lambda1, expressed as a fusion protein with the Escherichia coli maltose-binding protein (MBP), possesses a non-specific affinity for various nucleic acids. The study also showed that the first ten amino acids of the protein are sufficient for binding while a deletion of the first five amino acids prevented the binding to nucleic acids. These data indicate that the basic charges located at the extreme amino-terminal portion of the protein constitute the major determinant responsible for nucleic acids binding. Finally, a quantitative gel retardation assay using purified solubilized MBP-lambda1 fusion protein confirmed the importance of the amino-terminal region and also revealed that the lambda1 protein possesses a higher affinity for single-stranded RNA than for double-stranded nucleic acids, a property shared by many helicases.
authors.affiliation: Département de Microbiologie et Immunologie, Université de Montréal, Que., Canada.
authors.forename: M
authors.initials: M
authors.lastname: Bisaillon
authors.forename: G
authors.initials: G
authors.lastname: Lemay
mesh_terms: D001665:Binding Sites; D002213:Capsid / Q000235:genetics / Q000378:metabolism*; D036022:Capsid Proteins; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D016296:Mutagenesis; D012313:RNA / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012087:Reoviridae / Q000378:metabolism*; D013329:Structure-Activity Relationship
chemical_list: D036022:Capsid Proteins; D004268:DNA-Binding Proteins; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; C090196:lambda 1 protein, reovirus; D012313:RNA; D004247:DNA