Specific DNA binding by c-Myb: evidence for a double helix-turn-helix-related motif.
The c-Myb protein is a sequence-specific DNA binding protein that activates transcription in hematopoietic cells. Three imperfect repeats (R1, R2, and R3) that contain regularly spaced tryptophan residues form the DNA binding domain of c-Myb. A fragment of c-Myb that contained the R2 and R3 regions bound specifically to a DNA sequence recognized by c-Myb plus ten additional base pairs at the 3' end of the element. The R2R3 fragment was predicted to contain two consecutive helix-turn-helix (HTH) motifs with unconventional turns. Mutagenesis of amino acids in R2R3 at positions that correspond to DNA-contacting amino acids in other HTH-containing proteins abolished specific DNA binding without affecting nonspecific DNA interactions.
Gabrielsen
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Laboratoire d'Ingéniérie des Protéines, Centre d'Etudes de Saclay, Gif-sur-Yvette, France.
Sentenac
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Fromageot
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D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002645:Chickens; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D015345:Oligonucleotide Probes; D009857:Oncogenes; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D020598:Proto-Oncogene Proteins c-myb; D011994:Recombinant Proteins / Q000378:metabolism; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism*
D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D011518:Proto-Oncogene Proteins; D020598:Proto-Oncogene Proteins c-myb; D011994:Recombinant Proteins; D014157:Transcription Factors; D004247:DNA