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6hl0
From Proteopedia
Crystal Structure of Farnesoid X receptor (FXR) with bound NCoA-2 peptide
Structural highlights
Function[NR1H4_HUMAN] Ligand-activated transcription factor. Receptor for bile acids such as chenodeoxycholic acid, lithocholic acid and deoxycholic acid. Represses the transcription of the cholesterol 7-alpha-hydroxylase gene (CYP7A1) through the induction of NR0B2 or FGF19 expression, via two distinct mechanisms. Activates the intestinal bile acid-binding protein (IBABP). Activates the transcription of bile salt export pump ABCB11 by directly recruiting histone methyltransferase CARM1 to this locus.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedThe bile acid-sensing transcription factor farnesoid X receptor (FXR) regulates multiple metabolic processes. Modulation of FXR is desired to overcome several metabolic pathologies but pharmacological administration of full FXR agonists has been plagued by mechanism-based side effects. We have developed a modulator that partially activates FXR in vitro and in mice. Here we report the elucidation of the molecular mechanism that drives partial FXR activation by crystallography- and NMR-based structural biology. Natural and synthetic FXR agonists stabilize formation of an extended helix alpha11 and the alpha11-alpha12 loop upon binding. This strengthens a network of hydrogen bonds, repositions helix alpha12 and enables co-activator recruitment. Partial agonism in contrast is conferred by a kink in helix alpha11 that destabilizes the alpha11-alpha12 loop, a critical determinant for helix alpha12 orientation. Thereby, the synthetic partial agonist induces conformational states, capable of recruiting both co-repressors and co-activators leading to an equilibrium of co-activator and co-repressor binding. Molecular tuning of farnesoid X receptor partial agonism.,Merk D, Sreeramulu S, Kudlinzki D, Saxena K, Linhard V, Gande SL, Hiller F, Lamers C, Nilsson E, Aagaard A, Wissler L, Dekker N, Bamberg K, Schubert-Zsilavecz M, Schwalbe H Nat Commun. 2019 Jul 2;10(1):2915. doi: 10.1038/s41467-019-10853-2. PMID:31266946[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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Categories: Human | Large Structures | Kudlinzki, D | Linhard, V L | Merk, D | Saxena, K | Schubert-Zsilavecz, M | Schwalbe, H | Activator | Complex | Dna-binding | Nuclear protein | Receptor | Repressor
