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Live-Cell Imaging of Transcriptional Activity at DNA Double-Strand Breaks
Published on: September 20, 2021
Streptomyces telomeres contain a promoter
Yuh-ru Lin1, Mi-Young Hahn, Jung-Hye Roe
1Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Shih-Pai, Taipei 112, Taiwan.
Journal of Bacteriology
|December 9, 2008
Summary
Streptomyces telomeres possess unique promoter activity, binding RNA polymerase and driving gene expression. This novel finding challenges existing models of telomere function in bacteria and eukaryotes.
Area of Science:
- Microbiology
- Molecular Biology
- Genetics
Background:
- Streptomyces spp. linear chromosomes and plasmids have 3' single-strand overhangs with palindromic sequences.
- Telomere patching is thought to involve DNA synthesis primed by a terminal protein bound to 5' ends.
Purpose of the Study:
- To investigate the functional properties of Streptomyces telomere DNA.
- To determine if telomere DNA exhibits promoter activity.
Main Methods:
- In vitro binding assays with RNA polymerase holoenzyme.
- In vivo promoter activity assays using circular and linear plasmids in Streptomyces.
- Testing telomere promoter activity in Escherichia coli and yeast.
Main Results:
- A conserved 167-bp telomere DNA sequence strongly binds RNA polymerase holoenzyme.
- Telomere DNA exhibits promoter activity in both orientations in Streptomyces.
- This promoter activity is observed on linear plasmids during exponential growth.
- The telomere promoter functions in Escherichia coli and as a transcription enhancer in yeast.
Conclusions:
- Streptomyces telomeres possess intrinsic promoter activity, a novel observation in prokaryotes and eukaryotes.
- This telomere promoter function may be involved in replication, conjugal transfer, or gene expression.
- The conserved nature of this promoter suggests significant biological importance in Streptomyces.
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