title: RNA-binding properties of the 63 kDa protein encoded by the triple gene block of poa semilatent hordeivirus.
abstract: The 63 kDa '63K' movement protein encoded by the triple gene block of poa semilatent virus (PSLV) comprises the C-terminal NTPase/helicase domain and the N-terminal extension domain, which contains two positively charged sequence motifs, A and B. In this study, the in vitro RNA-binding properties of PSLV 63K and its mutants were analysed. Membrane-immobilized 63K and N-63K (isolated N-terminal extension domain) bound RNA at high NaCl concentrations. In contrast, C-63K (isolated NTPase/helicase domain) was able to bind RNA only at NaCl concentrations of up to 50 mM. In gel-shift assays, C-63K bound RNA to form complexes that were unable to enter an agarose gel, whereas complexes formed by N-63K could enter the gel. Full-length 63K formed both types of complexes. Visualization of the RNA-protein complexes formed by 63K, N-63K and C-63K by atomic force microscopy demonstrated that each complex had a different shape. Collectively, these data indicate that 63K has two distinct RNA-binding activities associated with the NTPase/helicase domain and the N-terminal extension domain. Mutations in either of the positively charged sequence motifs A and B had little effect on the RNA binding of the N-terminal extension domain, whereas mutations in both motifs together inhibited RNA binding. Hybrid viruses with mutations in motifs A and B were able to infect inoculated leaves of Nicotiana benthamiana plants, but were unable to move systemically to uninoculated leaves, suggesting that the RNA-binding activity of the N-terminal extension domain of PSLV 63K is associated with virus long-distance movement.
authors.affiliation: Department of Virology and A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia1.
authors.forename: N O
authors.initials: NO
authors.lastname: Kalinina
authors.affiliation: Department of Virology and A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia1.
authors.forename: D A
authors.initials: DA
authors.lastname: Rakitina
authors.affiliation: Department of Virology and A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia1.
authors.forename: N E
authors.initials: NE
authors.lastname: Yelina
authors.affiliation: Department of Virology and A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia1.
authors.forename: A A
authors.initials: AA
authors.lastname: Zamyatnin
authors.affiliation: Department of Virology and A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia1.
authors.forename: T A
authors.initials: TA
authors.lastname: Stroganova
authors.affiliation: M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya St, 117997 Moscow, Russia2.
authors.forename: D V
authors.initials: DV
authors.lastname: Klinov
authors.affiliation: M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya St, 117997 Moscow, Russia2.
authors.forename: V V
authors.initials: VV
authors.lastname: Prokhorov
authors.affiliation: M. M. Shemyakin and Yu. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 16/10 Miklukho-Maklaya St, 117997 Moscow, Russia2.
authors.forename: S V
authors.initials: SV
authors.lastname: Ustinova
authors.affiliation: Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, 32 Vavilova St, Moscow 117984, Russia3.
authors.forename: B K
authors.initials: BK
authors.lastname: Chernov
authors.affiliation: Institute of Plant Virology, Microbiology and Biosafety, Federal Biological Research Centre for Agriculture and Forestry, Messeweg 11/12, D-38104 Braunschweig, Germany4.
authors.forename: J
authors.initials: J
authors.lastname: Schiemann
authors.affiliation: Department of Virology and A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia1.
authors.forename: A G
authors.initials: AG
authors.lastname: Solovyev
authors.affiliation: Department of Virology and A. N. Belozersky Institute of Physico-Chemical Biology, Moscow State University, Moscow 119899, Russia1.
authors.forename: S Yu
authors.initials: SY
authors.lastname: Morozov
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D018625:Microscopy, Atomic Force; D008969:Molecular Sequence Data; D008970:Molecular Weight; D053830:Plant Viral Movement Proteins; D010942:Plant Viruses / Q000235:genetics*; D012313:RNA / Q000378:metabolism*; D014764:Viral Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D053830:Plant Viral Movement Proteins; D014764:Viral Proteins; D012313:RNA