BIOC 300B Lecture Notes - Lecture 15: Retinoic Acid Receptor, Nuclear Receptor, Protein Dimer
9 Mar 2018
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Document Summary
Bind nuclear hormone receptors ex: estrogen (an estradiol) Ligand binding domain (lbd) and dna-binding domain (dbd) Ligand binding does not affect dna-binding activity. Nucelar receptors have a common structure which has the activator function followed by dbd at one and and the ligand binding domain at the other. Differences in the relevant sizes may vary but structure remains conserved. Binds as homo/hetero dimers to repeat features in dna sequences that can be inverted, or spaced homodimer ex: estrogen receptor hetero = retinoic acid receptor. Upon binding, the change is minor and alters the conformation of one helix in the lbd. It folds over the bidding site and the nuclear receptor then regulated transcription of the promoter. This binding is not in uenced by gene expression as it only comes thru binding of the ligand and its consequent conformational change. Does not alter dna binding activity of receptor. Note: some nuclear hormone receptors are always present in the nucleus.
