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In vivo Application of the REMOTE-control System for the Manipulation of Endogenous Gene Expression
Published on: March 29, 2019
Influences on gene expression in vivo by a Shine-Dalgarno sequence
Haining Jin1, Qing Zhao, Ernesto I Gonzalez de Valdivia
1Department of Genetics, Microbiology and Toxicology, Stockholm University, S-106 91 Stockholm, Sweden.
Molecular Microbiology
|April 1, 2006
Summary
The Shine-Dalgarno sequence
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- The Shine-Dalgarno sequence is crucial for initiating mRNA translation by binding to the 16S rRNA in the small ribosomal subunit.
- Understanding the precise positioning of the Shine-Dalgarno sequence relative to the initiation codon is vital for controlling gene expression.
Purpose of the Study:
- To investigate how the location of the Shine-Dalgarno sequence (upstream or downstream of an initiation codon) affects gene expression.
- To determine the impact of Shine-Dalgarno sequence placement on translation initiation at multiple start sites.
- To explore the evolutionary implications of Shine-Dalgarno sequence distribution in bacterial genomes.
Main Methods:
- Comparative analysis of gene expression with upstream versus downstream Shine-Dalgarno sequences.
- Modification of natural Escherichia coli genes to study Shine-Dalgarno sequence effects.
- Introduction of stem-loop structures to modulate translation initiation.
- Bioinformatic analysis of Shine-Dalgarno sequence distribution in the E. coli K12 genome.
Main Results:
- An upstream Shine-Dalgarno sequence enhances gene expression, while a downstream sequence decreases it.
- When placed between two initiation codons, the Shine-Dalgarno sequence favors initiation at the second start site.
- Gene expression initiation can be shifted to the first start site by altering distances or weakening the second site.
- Stable stem-loop structures can abolish upstream initiation, suggesting ribosomal competition for Shine-Dalgarno binding.
Conclusions:
- The position of the Shine-Dalgarno sequence relative to the initiation codon significantly impacts translation efficiency.
- Ribosomal binding to the Shine-Dalgarno sequence can lead to competition between adjacent start sites.
- The avoidance of Shine-Dalgarno sequences in early coding regions of E. coli suggests evolutionary selection for precise translational control.
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