Basic helix-loop-helix protein MyoD displays modest DNA binding specificity.
The expression of MyoD can activate muscle specific genes and myogenic differentiation in many cell types. The hypothesis that the DNA binding specificity of MyoD is responsible for its biological specificity was tested. Homodimers of MyoD bind to E-box containing DNA with high affinity, but do not form stable and well defined complexes with heterologous DNA sequences. The physiologically active heterodimer of MyoD and E12 binds an oligonucleotide containing an E-box sequence with an affinity only two orders of magnitude higher than a completely unrelated DNA sequence, stressing the importance of cooperative interactions with other proteins of the transcriptional machinery for specific gene activation.
Künne
A G
AG
Department of Chemistry, ETH-Zurich, Switzerland.
Meierhans
D
D
Allemann
R K
RK
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D018257:Helix-Loop-Helix Motifs; D007700:Kinetics; D046911:Macromolecular Substances; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D017570:MyoD Protein / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D009838:Oligodeoxyribonucleotides; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D017354:Point Mutation; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism
D004268:DNA-Binding Proteins; D046911:Macromolecular Substances; D017570:MyoD Protein; D009838:Oligodeoxyribonucleotides; D010446:Peptide Fragments; D011994:Recombinant Proteins; D004247:DNA