title: Recruitment of the 40S ribosome subunit to the 3'-untranslated region (UTR) of a viral mRNA, via the eIF4 complex, facilitates cap-independent translation.
abstract: Barley yellow dwarf virus mRNA, which lacks both cap and poly(A) tail, has a translation element (3'-BTE) in its 3'-UTR essential for efficient translation initiation at the 5'-proximal AUG. This mechanism requires eukaryotic initiation factor 4G (eIF4G), subunit of heterodimer eIF4F (plant eIF4F lacks eIF4A), and 3'-BTE-5'-UTR interaction. Using fluorescence anisotropy, SHAPE (selective 2'-hydroxyl acylation analyzed by primer extension) analysis, and toeprinting, we found that (i) 40S subunits bind to BTE (Kd = 350 ± 30 nm), (ii) the helicase complex eIF4F-eIF4A-eIF4B-ATP increases 40S subunit binding (Kd = 120 ± 10 nm) to the conserved stem-loop I of the 3'-BTE by exposing more unpaired bases, and (iii) long distance base pairing transfers this complex to the 5'-end of the mRNA, where translation initiates. Although 3'-5' interactions have been recognized as important in mRNA translation, barley yellow dwarf virus employs a novel mechanism utilizing the 3'-UTR as the primary site of ribosome recruitment.
authors: From the Department of Chemistry, Hunter College and the Graduate Center, City University of New York, New York, New York 10065 and.
authors: Sohani Das
authors: SD
authors: Sharma
authors: the Departments of Plant Pathology and Microbiology and.
authors: Jelena J
authors: JJ
authors: Kraft
authors: the Departments of Plant Pathology and Microbiology and Biochemistry, Biophysics, Molecular Biology, and Microbiology, Iowa State University, Ames, Iowa 50011.
authors: W Allen
authors: WA
authors: Miller
authors: From the Department of Chemistry, Hunter College and the Graduate Center, City University of New York, New York, New York 10065 and dgoss@hunter.cuny.edu.
authors: Dixie J
authors: DJ
authors: Goss
mesh_terms: D020413:3' Untranslated Regions / Q000235:genetics*; D000255:Adenosine Triphosphate / Q000378:metabolism; D001483:Base Sequence; D039562:Eukaryotic Initiation Factor-4F / Q000378:metabolism*; D017793:Luteovirus / Q000235:genetics; D014176:Protein Biosynthesis; D020033:Protein Isoforms / Q000378:metabolism; D012315:RNA Caps; D020365:RNA Helicases / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D054682:Ribosome Subunits, Small, Eukaryotic / Q000378:metabolism*
chemical_list: D020413:3' Untranslated Regions; D039562:Eukaryotic Initiation Factor-4F; D020033:Protein Isoforms; D012315:RNA Caps; D012367:RNA, Viral; D000255:Adenosine Triphosphate; D020365:RNA Helicases
keywords: Plant Virus; Protein Synthesis; Protein-Nucleic Acid Interaction; RNA Structure; RNA Virus