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rRNA-mRNA base pairing stimulates a programmed -1 ribosomal frameshift
B Larsen1, N M Wills, R F Gesteland
1Howard Hughes Medical Institute, University of Utah, Salt Lake City 84112.
Journal of Bacteriology
|November 1, 1994
Summary
Shine-Dalgarno sequences guide ribosomal frameshifting during gene decoding. This interaction, crucial for Escherichia coli dnaX, differs from its role in translation initiation and can either stimulate or inhibit frameshifting based on its position.
Area of Science:
- Molecular Biology
- Genetics
- Microbiology
Background:
- Ribosomal frameshifting is essential for decoding certain genes.
- Shine-Dalgarno sequences typically initiate prokaryotic translation.
- The role of Shine-Dalgarno interactions in frameshifting is context-dependent.
Purpose of the Study:
- To investigate the mechanism of programmed -1 ribosomal frameshifting in Escherichia coli dnaX.
- To determine the role of Shine-Dalgarno sequence-16S rRNA base pairing in dnaX frameshifting.
- To compare frameshifting mechanisms across different genes.
Main Methods:
- Analysis of base pairing between 16S rRNA and mRNA at the 3' end.
- Investigating Shine-Dalgarno sequence positioning relative to frameshift sites.
- Comparing frameshifting efficiency in dnaX and release factor 2 genes.
Main Results:
- Base pairing between the 3' end of 16S rRNA and mRNA is critical for Escherichia coli dnaX -1 frameshifting.
- The Shine-Dalgarno sequence, located 10 nucleotides upstream of the dnaX shift site, facilitates -1 frameshifting.
- Altering the Shine-Dalgarno sequence position to 3 nucleotides upstream, as in release factor 2, inhibits frameshifting.
Conclusions:
- Shine-Dalgarno interactions within elongating ribosomes are a key mechanism for stimulating -1 frameshifting.
- The position of the Shine-Dalgarno sequence dictates its effect on ribosomal frameshifting.
- This mechanism is likely employed in the decoding of various genes requiring frameshifting.