How do thyroid hormone receptors bind to structurally diverse response elements?
Three classes of thyroid hormone response elements have been described. They are composed of two half-sites arranged either as a palindromic, a direct repeat or as an inverted palindromic array. Receptor homodimers as well as heterodimers can bind to all three types of response element. While the ligand binding domain of the receptors provides the major dimerization surface, asymmetric contacts between the DNA binding domains are necessary for binding to a direct repeat. Moreover, some recent findings suggest that in TR, compared to RXR, the ligand binding domain has a 180 degrees rotation with respect to the DNA binding domain. This feature could explain the preferential binding of the RXR-TR heterodimer to the direct repeat response element, in which RXR exclusively binds the 5' half-site, and of the TR homodimer to the inverted palindrome response element.
Desvergne
B
B
Institut de Biologie Animale, Université de Lausanne, Switzerland.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D016384:Consensus Sequence; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D008024:Ligands; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D011487:Protein Conformation; D011988:Receptors, Thyroid Hormone / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid; D012091:Repetitive Sequences, Nucleic Acid; D014157:Transcription Factors / Q000378:metabolism
D004268:DNA-Binding Proteins; D008024:Ligands; D011988:Receptors, Thyroid Hormone; D014157:Transcription Factors; D004247:DNA