DNA-binding domain and recognition sequence of the yeast BAS1 protein, a divergent member of the Myb family of transcription factors.
The yeast BAS1 protein is a transcriptional activator with an amino-terminal domain homologous to the DNA-binding domain of the oncoprotein Myb containing three imperfect tryptophan-rich repeats. In contrast to Myb-related transcription factors from higher eukaryotes, where the second and third repeat constitutes a minimal independent DNA-binding domain, all three repeats of BAS1 were found to be necessary for sequence-specific DNA binding. Moreover, an active DNA-binding subdomain was obtained only if the first repeat was enlarged in the amino-terminal direction to include 3 tryptophans and a 23-amino acid insertion and if 55 amino acids carboxyl-terminal to the third repeat were included. The BAS1 DNA-binding site was analyzed in detail and found to cover 8-9 base pairs with no similarity to the Myb recognition element. The binding site included a conserved hexameric TGACTC motif, the methylation of which abolished BAS1 binding, as well as a 3-base pair extension that seemed to have a modulatory effect on BAS1 affinity and where binding was less affected by methylation.
Department of Biochemistry, University of Oslo, Norway.
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Høvring
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Bostad
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Ording
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Myrset
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Gabrielsen
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002645:Chickens; D004271:DNA, Fungal / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D020598:Proto-Oncogene Proteins c-myb; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics*; D014364:Tryptophan / Q000378:metabolism
C061767:BAS1 protein, S cerevisiae; D004271:DNA, Fungal; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D014364:Tryptophan