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8e3n

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Current revision

Crystal structure of pregnane X receptor ligand binding domain complexed with rifamycin S

Structural highlights

8e3n is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.25Å
Ligands:
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

NR1I2_HUMAN Nuclear receptor that binds and is activated by variety of endogenous and xenobiotic compounds. Transcription factor that activates the transcription of multiple genes involved in the metabolism and secretion of potentially harmful xenobiotics, drugs and endogenous compounds. Activated by the antibiotic rifampicin and various plant metabolites, such as hyperforin, guggulipid, colupulone, and isoflavones. Response to specific ligands is species-specific. Activated by naturally occurring steroids, such as pregnenolone and progesterone. Binds to a response element in the promoters of the CYP3A4 and ABCB1/MDR1 genes.^[1] ^[2] ^[3] ^[4] ^[5] ^[6]

Publication Abstract from PubMed

Ligand-binding promiscuity in detoxification systems protects the body from toxicological harm but is a roadblock to drug development due to the difficulty in optimizing small molecules to both retain target potency and avoid metabolic events. Immense effort is invested in evaluating metabolism of molecules to develop safer, more effective treatments, but engineering specificity into or out of promiscuous proteins and their ligands is a challenging task. To better understand the promiscuous nature of detoxification networks, we have used X-ray crystallography to characterize a structural feature of pregnane X receptor (PXR), a nuclear receptor that is activated by diverse molecules (with different structures and sizes) to up-regulate transcription of drug metabolism genes. We found that large ligands expand PXR's ligand-binding pocket, and the ligand-induced expansion occurs through a specific unfavorable compound-protein clash that likely contributes to reduced binding affinity. Removing the clash by compound modification resulted in more favorable binding modes with significantly enhanced binding affinity. We then engineered the unfavorable ligand-protein clash into a potent, small PXR ligand, resulting in marked reduction in PXR binding and activation. Structural analysis showed that PXR is remodeled, and the modified ligands reposition in the binding pocket to avoid clashes, but the conformational changes result in less favorable binding modes. Thus, ligand-induced binding pocket expansion increases ligand-binding potential of PXR but is an unfavorable event; therefore, drug candidates can be engineered to expand PXR's ligand-binding pocket and reduce their safety liability due to PXR binding.

Structure-guided approach to modulate small molecule binding to a promiscuous ligand-activated protein.,Lin W, Huber AD, Poudel S, Li Y, Seetharaman J, Miller DJ, Chen T Proc Natl Acad Sci U S A. 2023 Mar 7;120(10):e2217804120. doi: , 10.1073/pnas.2217804120. Epub 2023 Feb 27. PMID:36848571^[7]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Lehmann JM, McKee DD, Watson MA, Willson TM, Moore JT, Kliewer SA. The human orphan nuclear receptor PXR is activated by compounds that regulate CYP3A4 gene expression and cause drug interactions. J Clin Invest. 1998 Sep 1;102(5):1016-23. PMID:9727070 doi:10.1172/JCI3703
↑ Zhang J, Kuehl P, Green ED, Touchman JW, Watkins PB, Daly A, Hall SD, Maurel P, Relling M, Brimer C, Yasuda K, Wrighton SA, Hancock M, Kim RB, Strom S, Thummel K, Russell CG, Hudson JR Jr, Schuetz EG, Boguski MS. The human pregnane X receptor: genomic structure and identification and functional characterization of natural allelic variants. Pharmacogenetics. 2001 Oct;11(7):555-72. PMID:11668216
↑ Geick A, Eichelbaum M, Burk O. Nuclear receptor response elements mediate induction of intestinal MDR1 by rifampin. J Biol Chem. 2001 May 4;276(18):14581-7. Epub 2001 Jan 31. PMID:11297522 doi:10.1074/jbc.M010173200
↑ Li Y, Ross-Viola JS, Shay NF, Moore DD, Ricketts ML. Human CYP3A4 and murine Cyp3A11 are regulated by equol and genistein via the pregnane X receptor in a species-specific manner. J Nutr. 2009 May;139(5):898-904. doi: 10.3945/jn.108.103572. Epub 2009 Mar 18. PMID:19297428 doi:10.3945/jn.108.103572
↑ Watkins RE, Maglich JM, Moore LB, Wisely GB, Noble SM, Davis-Searles PR, Lambert MH, Kliewer SA, Redinbo MR. 2.1 A crystal structure of human PXR in complex with the St. John's wort compound hyperforin. Biochemistry. 2003 Feb 18;42(6):1430-8. PMID:12578355 doi:10.1021/bi0268753
↑ Teotico DG, Bischof JJ, Peng L, Kliewer SA, Redinbo MR. Structural basis of human pregnane X receptor activation by the hops constituent colupulone. Mol Pharmacol. 2008 Dec;74(6):1512-20. doi: 10.1124/mol.108.050732. Epub 2008 Sep, 2. PMID:18768384 doi:10.1124/mol.108.050732
↑ Lin W, Huber AD, Poudel S, Li Y, Seetharaman J, Miller DJ, Chen T. Structure-guided approach to modulate small molecule binding to a promiscuous ligand-activated protein. Proc Natl Acad Sci U S A. 2023 Mar 7;120(10):e2217804120. PMID:36848571 doi:10.1073/pnas.2217804120

1 Structural highlights
2 Function
3 Publication Abstract from PubMed
4 See Also
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/8e3n"

@@ Line 4: / Line 4: @@
 == Structural highlights ==
 <table><tr><td colspan='2'>[[8e3n]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8E3N OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8E3N FirstGlance]. <br>
-</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=VA0:Rifamycin+S'>VA0</scene></td></tr>
+</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.25&#8491;</td></tr>
+<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=VA0:Rifamycin+S'>VA0</scene></td></tr>
 <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8e3n FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8e3n OCA], [https://pdbe.org/8e3n PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8e3n RCSB], [https://www.ebi.ac.uk/pdbsum/8e3n PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8e3n ProSAT]</span></td></tr>
 </table>
@@ Line 18: / Line 19: @@
 </div>
 <div class="pdbe-citations 8e3n" style="background-color:#fffaf0;"></div>
+==See Also==
+*[[Pregnane X receptor 3D structures|Pregnane X receptor 3D structures]]
 == References ==
 <references/>

8e3n

From Proteopedia

Current revision

Crystal structure of pregnane X receptor ligand binding domain complexed with rifamycin S

Structural highlights

Function

Publication Abstract from PubMed

See Also

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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