Intrinsically bent DNA in the promoter regions of the yeast GAAL1-10 and GAL80 genes.
Circular permutation analysis has detected fairly strong sites of intrinsic DNA bending on the promoter regions of the yeast GAL1-10 and GAL80 genes. These bends lie in functionally suggestive locations. On the promoter of the GAL1-10 structural genes, strong bends bracket nucleosome B, which lies between the UAS(G) and the GAL1 TATA. These intrinsic bends could help position nucleosome B. Nucleosome B plus two other promoter nucleosomes protect the TATA and start site elements in the inactive state of expression but are completely disrupted (removed) when GAL1-10 expression is induced. The strongest intrinsic bend ( approximately 70 degrees ) lies at the downstream edge of nucleosome B; this places it approximately 30 base pairs upstream of the GAL1 TATA, a position that could allow it to be involved in GAL1 activation in several ways, including the recruitment of a yeast HMG protein that is required for the normally robust level of GAL1 expression in the induced state (Paull, T., Carey, M., and Johnson, R. (1996) Genes Dev. 10, 2769-2781). On the regulatory gene GAL80, the single bend lies in the non-nucleosomal hypersensitive region, between a GAL80-specific far upstream promoter element and the more gene-proximal promoter elements. GAL80 promoter region nucleosomes contain no intrinsically bent DNA.
Bash
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Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287-1604, USA.
Vargason
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JM
Cornejo
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Ho
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Lohr
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D004271:DNA, Fungal / Q000737:chemistry* / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics*; D005798:Genes, Bacterial; D005800:Genes, Fungal / Q000235:genetics*; D005809:Genes, Regulator; D007438:Introns; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D012441:Saccharomyces cerevisiae / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics*
D004271:DNA, Fungal; D005656:Fungal Proteins; D014157:Transcription Factors