کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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3427106 | 1227361 | 2007 | 11 صفحه PDF | دانلود رایگان |
Tobacco necrosis necrovirus (TNV) RNA lacks both a 5′ cap and a poly(A) tail but is translated efficiently, owing in part to a Barley yellow dwarf virus (BYDV)-like cap-independent translation element (BTE) in its 3′ untranslated region (UTR). Here, we identify sequence downstream of the BTE that is necessary for poly(A) tail-independent translation in vivo by using RNA encoding a luciferase reporter gene flanked by viral UTRs. Deletions and point mutations caused loss of translation that was restored by adding a poly(A) tail, and not by adding a 5′ cap. The two 3′-proximal stem–loops in the viral genome contribute to poly(A) tail-independent translation, as well as RNA replication. For all necroviruses, we predict a conserved 3′ UTR secondary structure that includes the BTE at one end of a long helical axis and the stem–loops required for poly(A) tail-independent translation and RNA replication at the other end. This work shows that a viral genome can harbor distinct cap- and poly(A) tail-mimic sequences in the 3′ UTR.
Journal: Virology - Volume 358, Issue 2, 20 February 2007, Pages 448–458