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Updated: Jul 20, 2026
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DNA-Tethered RNA Polymerase for Programmable In vitro Transcription and Molecular Computation
Published on: December 29, 2021
Genes with internal repeats require the THO complex for transcription.
Vladimir Voynov1, Kevin J Verstrepen, An Jansen
1Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA.
Summary
The THO complex is crucial for yeast gene expression, particularly those with repetitive DNA sequences. Its absence causes transcription issues and genetic instability, which can be overcome by topoisomerase I.
Area of Science:
- Molecular Biology
- Yeast Genetics
- Gene Expression Regulation
Background:
- The THO complex is an evolutionarily conserved protein assembly.
- It is recruited to actively transcribed genes.
- Efficient expression of certain yeast genes, like FLO11, depends on the THO complex.
Purpose of the Study:
- To investigate the role of the THO complex in the expression of yeast genes containing long internal tandem repeats.
- To understand the mechanism by which the THO complex facilitates transcription elongation and maintains genetic stability.
Main Methods:
- Analysis of FLO11 gene expression in wild-type (Tho+) and THO-deficient (Tho-) yeast strains.
- Genetic manipulation of the FLO11 gene to remove tandem repeats.
- Assessing genetic instability in tandem repeat regions.
- Investigating the effect of topoisomerase I overexpression on transcription in Tho- mutants.
Main Results:
- Transcription elongation of FLO11 is impaired in the tandem repeat region in Tho- mutants, leading to loss of function.
- Tandem repeats in FLO11 become genetically unstable in Tho- mutants.
- A FLO11 gene lacking tandem repeats shows similar transcription levels in both Tho+ and Tho- strains.
- Overexpression of topoisomerase I suppresses the transcription defect observed in Tho- mutants.
Conclusions:
- The THO complex is essential for efficient transcription elongation and genetic stability of yeast genes with long internal tandem repeats.
- The THO complex likely functions to resolve aberrant DNA structures that form during transcription of repetitive sequences.
- Topoisomerase I activity is implicated in counteracting the negative effects of THO complex deficiency on transcription.
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