title: 3' cap-independent translation enhancers of plant viruses.
abstract: In the absence of a 5' cap, plant positive-strand RNA viruses have evolved a number of different elements in their 3' untranslated region (UTR) to attract initiation factors and/or ribosomes to their templates. These 3' cap-independent translational enhancers (3' CITEs) take different forms, such as I-shaped, Y-shaped, T-shaped, or pseudoknotted structures, or radiate multiple helices from a central hub. Common features of most 3' CITEs include the ability to bind a component of the translation initiation factor eIF4F complex and to engage in an RNA-RNA kissing-loop interaction with a hairpin loop located at the 5' end of the RNA. The two T-shaped structures can bind to ribosomes and ribosomal subunits, with one structure also able to engage in a simultaneous long-distance RNA-RNA interaction. Several of these 3' CITEs are interchangeable and there is evidence that natural recombination allows exchange of modular CITE units, which may overcome genetic resistance or extend the virus's host range.
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742; email: simona@umd.edu.
authors.forename: Anne E
authors.initials: AE
authors.lastname: Simon
authors.forename: W Allen
authors.initials: WA
authors.lastname: Miller
mesh_terms: D020413:3' Untranslated Regions; D010942:Plant Viruses / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014176:Protein Biosynthesis; D012315:RNA Caps / Q000235:genetics* / Q000378:metabolism; D012367:RNA, Viral / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D020413:3' Untranslated Regions; D012315:RNA Caps; D012367:RNA, Viral; D014764:Viral Proteins