Structures required for poly(A) tail-independent translation overlap with, but are distinct from, cap-independent translation and RNA replication signals at the 3' end of Tobacco necrosis virus RNA

Biblio

Publication Type:

Journal Article

Source:

Virology, Volume 358, Number 2, p.448-58 (2007)

ISBN:

0042-6822 (Print)<br/>0042-6822 (Linking)

Accession Number:

17023016

Keywords:

3' Untranslated Regions/chemistry/ physiology, Avena sativa, Base Sequence, Genome, Viral, Molecular Sequence Data, Nucleic Acid Conformation, Protein Biosynthesis, Protoplasts, RNA, Viral/ biosynthesis, Tombusviridae/ genetics

Abstract:

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.

Notes:

Shen, Ruizhong<br/>Miller, W Allen<br/>R01 GM067104/GM/NIGMS NIH HHS/United States<br/>Research Support, N.I.H., Extramural<br/>Research Support, Non-U.S. Gov't<br/>United States<br/>Virology. 2007 Feb 20;358(2):448-58. Epub 2006 Oct 4.