title: An unusual internal ribosomal entry site of inverted symmetry directs expression of a potato leafroll polerovirus replication-associated protein.
abstract: Potato leafroll polerovirus (PLRV) genomic RNA acts as a polycistronic mRNA for the production of proteins P0, P1, and P2 translated from the 5'-proximal half of the genome. Within the P1 coding region we identified a 5-kDa replication-associated protein 1 (Rap1) essential for viral multiplication. An internal ribosome entry site (IRES) with unusual structure and location was identified that regulates Rap1 translation. Core structural elements for internal ribosome entry include a conserved AUG codon and a downstream GGAGAGAGAGG motif with inverted symmetry. Reporter gene expression in potato protoplasts confirmed the internal ribosome entry function. Unlike known IRES motifs, the PLRV IRES is located completely within the coding region of Rap1 at the center of the PLRV genome.
authors.affiliation: Fraunhofer-Institut für Molekularbiologie, Abteilung Genom und Proteomforschung, Auf dem Aberg 1, 57392 Schmallenberg, Germany.
authors.forename: Hannah Miriam
authors.initials: HM
authors.lastname: Jaag
authors.forename: Lawrence
authors.initials: L
authors.lastname: Kawchuk
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Rohde
authors.forename: Rainer
authors.initials: R
authors.lastname: Fischer
authors.forename: Neil
authors.initials: N
authors.lastname: Emans
authors.forename: Dirk
authors.initials: D
authors.lastname: Prüfer
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D018387:Codon, Initiator / Q000235:genetics; D016679:Genome, Viral; D017793:Luteovirus / Q000235:genetics* / Q000302:isolation & purification / Q000502:physiology; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012367:RNA, Viral / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D012270:Ribosomes / Q000235:genetics; D017386:Sequence Homology, Amino Acid; D011198:Solanum tuberosum / Q000821:virology; D014764:Viral Proteins / Q000235:genetics*; D014779:Virus Replication / Q000235:genetics
chemical_list: D018387:Codon, Initiator; D012367:RNA, Viral; D014764:Viral Proteins