Publication Type:Journal Article
Source:J Virol, Volume 78, Number 9, p.4655-64 (2004)
ISBN:0022-538X (Print)<br/>0022-538X (Linking)
Keywords:3' Untranslated Regions/ genetics, Base Sequence, Enhancer Elements, Genetic, Gene Expression Regulation, Viral, Luteovirus/ genetics, Molecular Sequence Data, Protein Biosynthesis, RNA Caps/ metabolism, RNA, Viral/genetics, Tombusviridae/ genetics
RNAs of many viruses are translated efficiently in the absence of a 5' cap structure. The tobacco necrosis virus (TNV) genome is an uncapped, nonpolyadenylated RNA whose translation mechanism has not been well investigated. Computational analysis predicted a cap-independent translation element (TE) within the 3' untranslated region (3' UTR) of TNV RNA that resembles the TE of barley yellow dwarf virus (BYDV), a luteovirus. Here we report that such a TE does indeed exist in the 3' UTR of TNV strain D. Like the BYDV TE, the TNV TE (i) functions both in vitro and in vivo, (ii) requires additional sequence for cap-independent translation in vivo, (iii) has a similar secondary structure and the conserved sequence CGGAUCCUGGGAAACAGG, (iv) is inactivated by a four-base duplication in this conserved sequence, (v) can function in the 5' UTR, and (vi) when located in its natural 3' location, may form long-distance base pairing with the viral 5' UTR that is conserved and probably required. The TNV TE differs from the BYDV TE by having only three helical domains instead of four. Similar structures were found in all members of the Necrovirus genus of the Tombusviridae family, except satellite tobacco necrosis virus, which harbors a different 3' cap-independent translation domain. The presence of the BYDV-like TE in select genera of different families indicates that phylogenetic distribution of TEs does not follow standard viral taxonomic relationships. We propose a new class of cap-independent TE called BYDV-like TE.
Shen, Ruizhong<br/>Miller, W Allen<br/>R01 GM067104/GM/NIGMS NIH HHS/United States<br/>R01 GM67104-01A1/GM/NIGMS NIH HHS/United States<br/>Research Support, U.S. Gov't, Non-P.H.S.<br/>Research Support, U.S. Gov't, P.H.S.<br/>United States<br/>J Virol. 2004 May;78(9):4655-64.