title: A ribosome-binding, 3' translational enhancer has a T-shaped structure and engages in a long-distance RNA-RNA interaction.
abstract: Many plant RNA viruses contain elements in their 3' untranslated regions (3' UTRs) that enhance translation. The PTE (Panicum mosaic virus-like translational enhancer) of Pea enation mosaic virus (PEMV) binds to eukaryotic initiation factor 4E (eIF4E), but how this affects translation from the 5' end is unknown. We have discovered a three-way branched element just upstream of the PEMV PTE that engages in a long-distance kissing-loop interaction with a coding sequence hairpin that is critical for the translation of a reporter construct and the accumulation of the viral genome in vivo. Loss of the long-distance interaction was more detrimental than elimination of the adjacent PTE, indicating that the RNA-RNA interaction supports additional translation functions besides relocating the PTE to the 5' end. The branched element is predicted by molecular modeling and molecular dynamics to form a T-shaped structure (TSS) similar to the ribosome-binding TSS of Turnip crinkle virus (TCV). The PEMV element binds to plant 80S ribosomes with a K(d) (dissociation constant) of 0.52 μM and to 60S subunits with a K(d) of 0.30 μM. Unlike the TCV TSS, the PEMV element also binds 40S subunits (K(d), 0.36 μM). Mutations in the element that suppressed translation reduced either ribosome binding or the RNA-RNA interaction, suggesting that ribosome binding is important for function. This novel, multifunctional element is designated a kl-TSS (kissing-loop T-shaped structure) to distinguish it from the TCV TSS. The kl-TSS has sequence and structural features conserved with the upper portion of most PTE-type elements, which, with the exception of the PEMV PTE, can engage in similar long-distance RNA-RNA interactions.
authors: Department of Cell Biology and Molecular Genetics, University of Maryland-College Park, College Park, Maryland, USA.
authors: Feng
authors: F
authors: Gao
authors: Wojciech
authors: W
authors: Kasprzak
authors: Vera A
authors: VA
authors: Stupina
authors: Bruce A
authors: BA
authors: Shapiro
authors: Anne E
authors: AE
authors: Simon
mesh_terms: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D019184:Carmovirus / Q000235:genetics / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D016679:Genome, Viral; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009029:Mosaic Viruses / Q000235:genetics* / Q000378:metabolism*; D009690:Nucleic Acid Conformation; D014176:Protein Biosynthesis; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D012270:Ribosomes / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D012367:RNA, Viral