Distinct DNA binding preferences for the c-Myc/Max and Max/Max dimers.
The transcription factor c-Myc and its dimerisation partner Max are members of the basic/helix-loop-helix/leucine-zipper (bHLH-Z) family and bind to the DNA core sequence CACGTG. Using a site-selection protocol, we determined the complete 12 base pair consensus binding sites of c-Myc/Max (RACCACGTGGTY) and Max/Max (RANCACGTGNTY) dimers. We find that the c-Myc/Max dimer fails to bind the core when it is flanked by a 5'T or a 3'A, while the Max/Max dimer readily binds such sequences. Furthermore we show that inappropriate flanking sequences preclude transactivation by c-Myc in vivo. In conclusion, Max/Max dimers are less discriminatory than c-Myc/Max and may regulate other genes in addition to c-Myc/Max targets.
Solomon
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DL
Growth Control and Development Laboratory, Imperial Cancer Research Fund, London, UK.
Amati
B
B
Land
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H
D001483:Base Sequence; D050976:Basic-Leucine Zipper Transcription Factors; D001665:Binding Sites; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000378:metabolism*; D018257:Helix-Loop-Helix Motifs; D016350:Leucine Zippers; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes / Q000737:chemistry; D016271:Proto-Oncogene Proteins c-myc / Q000378:metabolism*; D011994:Recombinant Proteins; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors; D015533:Transcriptional Activation
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; C067850:Myc associated factor X; D015345:Oligonucleotide Probes; D016271:Proto-Oncogene Proteins c-myc; D011994:Recombinant Proteins; D015534:Trans-Activators; D014157:Transcription Factors