Cation-dependent folding of 3' cap-independent translation elements facilitates interaction of a 17-nucleotide conserved sequence with eIF4G

Biblio

Publication Type:

Journal Article

Source:

Nucleic Acids Res, Volume 41, Number 5, p.3398-413 (2013)

ISBN:

1362-4962 (Electronic)<br/>0305-1048 (Linking)

Accession Number:

23361463

Keywords:

Base Sequence, Binding Sites, Conserved Sequence, Eukaryotic Initiation Factor-4G/chemistry/ genetics, Gene Expression, Gene Expression Regulation, Viral, Genes, Reporter, Luciferases, Firefly/biosynthesis/genetics, Luteovirus/ genetics, Magnesium Chloride/chemistry, Molecular Sequence Data, Peptide Chain Initiation, Translational, Plant Proteins/chemistry/ genetics, Potassium/chemistry, Protein Binding, Regulatory Sequences, Ribonucleic Acid, RNA Folding, RNA, Messenger/biosynthesis/genetics, RNA, Viral/chemistry/ genetics, Untranslated Regions

Abstract:

The 3'-untranslated regions of many plant viral RNAs contain cap-independent translation elements (CITEs) that drive translation initiation at the 5'-end of the mRNA. The barley yellow dwarf virus-like CITE (BTE) stimulates translation by binding the eIF4G subunit of translation initiation factor eIF4F with high affinity. To understand this interaction, we characterized the dynamic structural properties of the BTE, mapped the eIF4G-binding sites on the BTE and identified a region of eIF4G that is crucial for BTE binding. BTE folding involves cooperative uptake of magnesium ions and is driven primarily by charge neutralization. Footprinting experiments revealed that functional eIF4G fragments protect the highly conserved stem-loop I and a downstream bulge. The BTE forms a functional structure in the absence of protein, and the loop that base pairs the 5'-untranslated region (5'-UTR) remains solvent-accessible at high eIF4G concentrations. The region in eIF4G between the eIF4E-binding site and the MIF4G region is required for BTE binding and translation. The data support the model in which the eIF4F complex binds directly to the BTE which base pairs simultaneously to the 5'-UTR, allowing eIF4F to recruit the 40S ribosomal subunit to the 5'-end.

Notes:

Kraft, Jelena J<br/>Treder, Krzysztof<br/>Peterson, Mariko S<br/>Miller, W Allen<br/>2R01 GM067104/GM/NIGMS NIH HHS/United States<br/>R01 GM067104/GM/NIGMS NIH HHS/United States<br/>Research Support, American Recovery and Reinvestment Act<br/>Research Support, N.I.H., Extramural<br/>Research Support, U.S. Gov't, Non-P.H.S.<br/>England<br/>Nucleic Acids Res. 2013 Mar 1;41(5):3398-413. doi: 10.1093/nar/gkt026. Epub 2013 Jan 29.