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Generating yeast transcriptional activators containing no yeast protein sequences
1Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Nature
|March 21, 1991
Summary
Researchers identified bacterial peptides that activate transcription in yeast. Using a modified LexA protein, they confirmed that approximately 1% of Escherichia coli DNA fragments encode these novel transcriptional activating regions.
Area of Science:
- Molecular Biology
- Genetics
- Biochemistry
Background:
- Previous studies suggested bacterial peptides could activate transcription in yeast, but findings were questioned due to the DNA-binding protein used.
- Criticism focused on the potential inherent activating regions within the GAL4 DNA-binding domain and failures with a truncated LexA domain.
Purpose of the Study:
- To re-evaluate the identification of bacterial transcriptional activating sequences.
- To determine if a complete bacterial DNA-binding protein (LexA) would yield similar results to the original experiment.
Main Methods:
- Fusion of Escherichia coli genomic DNA fragments to the complete LexA protein (LexA(1-202)).
- Assay for transcriptional activation in yeast.
- Sequence determination of identified activating regions.
Main Results:
- Approximately 1% of the tested E. coli DNA fragments encoded functional transcriptional activating regions when fused to intact LexA.
- All identified activating regions exhibited an excess of acidic amino acids.
- Results mirrored the initial findings, validating the existence of bacterial transcriptional activators.
Conclusions:
- The study confirms the existence of novel transcriptional activating regions within Escherichia coli genomic DNA.
- The choice of DNA-binding protein is crucial for identifying these bacterial activators.
- Acidic amino acid content appears to be a characteristic feature of these identified activating regions.