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2A peptides provide distinct solutions to driving stop-carry on translational recoding
Pamila Sharma1, Fu Yan, Victoria A Doronina
1RNA Biology Group and Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Newcastle upon Tyne NE2 4HH, UK.
Nucleic Acids Research
|December 6, 2011
Summary
Viral 2A peptides cause
Area of Science:
- Molecular Biology
- Virology
- Biochemistry
Background:
- Viral protein expression often involves non-canonical decoding events called recoding during translation.
- 2A oligopeptides mediate a specific recoding event known as 'stop-carry on' recoding.
Purpose of the Study:
- To investigate the mechanism by which 2A peptides induce stop codon-independent translation termination and reinitiation.
- To determine the importance of N-terminal amino acids in 2A peptide activity.
Main Methods:
- Mutagenesis of 2A peptide sequences.
- Analysis of translation termination and reinitiation events.
Main Results:
- Nascent 2A peptides interact with the ribosomal exit tunnel, causing translation to terminate at the final Pro codon instead of a stop codon.
- Mutagenesis revealed that amino acid identity at nearly all positions of a 2A peptide is crucial for its activity.
- Replacing the final Pro codon with a stop codon stalls ribosome function and inhibits protein release.
Conclusions:
- 2A peptides represent specific solutions for positioning the conserved C-terminus to promote recoding.
- Nascent 2A peptide:ribosome interactions likely alter ribosomal structure to facilitate this unusual termination and reinitiation process.
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