title: Beet necrotic yellow vein virus 42 kDa triple gene block protein binds nucleic acid in vitro.
abstract: The triple gene block (TGB) of beet necrotic yellow vein virus RNA 2 is required for cell-to-cell movement of the virus RNA. The protein P42 encoded by the 5'-proximal gene of the TGB has consensus sequence motifs characteristic of an ATP/GTP-dependent helicase. P42 was over-expressed in Escherichia coli and shown to bind both single- and double-stranded RNA and DNA by Northwestern blotting. Site-directed mutagenesis located the nucleic acid-binding domain to the N-terminal 24 amino acids of the protein and a point mutation or deletions in the region of P42 containing the helicase consensus sequences did not affect nucleic acid-binding activity of the immobilized protein. Electrophoretic mobility-shift assays revealed that P42 also binds nucleic acids in solution and that deletion of the N-terminal region inhibits this binding. Mutations in both the N-terminal nucleic acid-binding domain and the helicase domain blocked infection of leaves, indicating that both regions of P42 are important for its activity in vivo.
authors.affiliation: Institut de Biologie Moléculaire des Plantes du CNRS, Strasbourg, France.
authors.forename: C
authors.initials: C
authors.lastname: Bleykasten
authors.forename: D
authors.initials: D
authors.lastname: Gilmer
authors.forename: H
authors.initials: H
authors.lastname: Guilley
authors.forename: K E
authors.initials: KE
authors.lastname: Richards
authors.forename: G
authors.initials: G
authors.lastname: Jonard
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D004247:DNA / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010942:Plant Viruses / Q000737:chemistry* / Q000235:genetics; D012313:RNA / Q000378:metabolism*; D012328:RNA Viruses / Q000737:chemistry* / Q000235:genetics; D011994:Recombinant Proteins / Q000378:metabolism; D013329:Structure-Activity Relationship; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D014764:Viral Proteins; D012313:RNA; D004247:DNA