title: The RNA helicase CI from plum pox potyvirus has two regions involved in binding to RNA.
abstract: The plum pox virus (PPV) protein CI is an RNA helicase, whose function in the virus replication is still unknown. Recently, an RNA binding domain was mapped to a region of the CI protein that includes the arginine-rich motif VI typical of RNA helicases of the superfamily SF2. In the present study, a second region involved in RNA binding activity of the CI protein has been identified. Northwestern assays with a series of maltose-binding protein fusions that contain different CI fragments showed that the RNA binding domain is located between residues 75 and 143. This segment contains the two most amino-terminal conserved domains of RNA helicases: I, involved in NTP binding, and Ia, of unknown function. The results can be explained in the context of a close interdependence between the protein regions involved in the NTPase and RNA binding activities that is expected for an RNA helicase.
authors.affiliation: Centro Nacional de Biotecnología (CSIC), Campus de la Universidad Autónoma de Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Fernández
authors.forename: J A
authors.initials: JA
authors.lastname: García
mesh_terms: D001665:Binding Sites; D006863:Hydrogen-Ion Concentration; D007181:Inclusion Bodies, Viral / Q000378:metabolism; D017801:Plum Pox Virus / Q000201:enzymology*; D012313:RNA / Q000378:metabolism*; D020365:RNA Helicases; D012316:RNA Nucleotidyltransferases / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism*
chemical_list: D014764:Viral Proteins; D012313:RNA; D012316:RNA Nucleotidyltransferases; D020365:RNA Helicases