title: Functions of the 5'- and 3'-untranslated regions of tobamovirus RNA.
abstract: The tobamovirus genome is a 5'-m(7)G-capped RNA that carries a tRNA-like structure at its 3'-terminus. The genomic RNA serves as the template for both translation and negative-strand RNA synthesis. The 5'- and 3'-untranslated regions (UTRs) of the genomic RNA contain elements that enhance translation, and the 3'-UTR also contains the elements necessary for the initiation of negative-strand RNA synthesis. Recent studies using a cell-free viral RNA translation-replication system revealed that a 70-nucleotide region containing a part of the 5'-UTR is bound cotranslationally by tobacco mosaic virus (TMV) replication proteins translated from the genomic RNA and that the binding leads the genomic RNA to RNA replication pathway. This mechanism explains the cis-preferential replication of TMV by the replication proteins. The binding also inhibits further translation to avoid a fatal ribosome-RNA polymerase collision, which might arise if translation and negative-strand synthesis occur simultaneously on a single genomic RNA molecule. Therefore, the 5'- and 3'-UTRs play multiple important roles in the life cycle of tobamovirus.
authors: Plant-Microbe Interactions Research Unit, Division of Plant Sciences, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan.
authors: Tetsuya
authors: T
authors: Chujo
authors: Plant-Microbe Interactions Research Unit, Division of Plant Sciences, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan.
authors: Kazuhiro
authors: K
authors: Ishibashi
authors: Plant-Microbe Interactions Research Unit, Division of Plant Sciences, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan.
authors: Shuhei
authors: S
authors: Miyashita
authors: Plant-Microbe Interactions Research Unit, Division of Plant Sciences, National Institute of Agrobiological Sciences, 2-1-2 Kannondai, Tsukuba, Ibaraki 305-8602, Japan. Electronic address: ishika32@affrc.go.jp.
authors: Masayuki
authors: M
authors: Ishikawa
mesh_terms: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D014176:Protein Biosynthesis; D059370:RNA Folding; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D017898:Tobamovirus / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic; D014764:Viral Proteins / Q000378:metabolism; D014779:Virus Replication
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D014764:Viral Proteins
keywords: RNA; Replication; Tobacco mosaic virus; Tomato mosaic virus; Translation; Untranslated region