Intracellular receptors - Revision history

Alexander Berchansky at 13:53, 4 March 2024

2024-03-04T13:53:07Z

←Older revision		Revision as of 13:53, 4 March 2024
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	<scene name='51/516465/Cv/4'>9-cis retinoid acid binds to RXRα LBD in a hydrophobic pocket</scene>. {{Template:ColorKey_Hydrophobic}}, {{Template:ColorKey_Polar}}. <scene name='51/516465/Cv/5'>9-cis retinoid acid is in a hydrophobic pocket</scene>. The ligand-binding residues are conserved in the 3 classes of RXR.		<scene name='51/516465/Cv/4'>9-cis retinoid acid binds to RXRα LBD in a hydrophobic pocket</scene>. {{Template:ColorKey_Hydrophobic}}, {{Template:ColorKey_Polar}}. <scene name='51/516465/Cv/5'>9-cis retinoid acid is in a hydrophobic pocket</scene>. The ligand-binding residues are conserved in the 3 classes of RXR.
	*[[Estrogen receptor]]		*[[Estrogen receptor]]
-	<scene name='Estrogen_receptor/Cv/1'>Click here to see the difference between conformations</scene> of estrogen receptor α complexed with raloxifene and a corepressor peptide (morph was taken from [http://molmovdb.org/cgi-bin/movie.cgi Gallery of Morphs] of the [http://molmovdb.org Yale Morph Server]).	+	<scene name='Estrogen_receptor/Cv/1'>Click here to see the difference between conformations</scene> of estrogen receptor α complexed with [[raloxifene]] and a corepressor peptide (morph was taken from [http://molmovdb.org/cgi-bin/movie.cgi Gallery of Morphs] of the [http://molmovdb.org Yale Morph Server]).

	Structure of estradiol metal chelate and estrogen receptor complex: The basis for designing a new class of SERMs<ref>PMID: 21473635</ref>.		Structure of estradiol metal chelate and estrogen receptor complex: The basis for designing a new class of SERMs<ref>PMID: 21473635</ref>.

Alexander Berchansky at 11:32, 27 April 2022

2022-04-27T11:32:11Z

←Older revision		Revision as of 11:32, 27 April 2022
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	*[[Hormone]]		*[[Hormone]]
	*[[Receptor]]		*[[Receptor]]
-		+	*[[Signal transduction]]
	</StructureSection>		</StructureSection>
	== References ==		== References ==
	<references/>		<references/>

Alexander Berchansky at 13:42, 23 May 2021

2021-05-23T13:42:51Z

(Difference between revisions)

Alexander Berchansky at 13:27, 23 May 2021

2021-05-23T13:27:42Z

Alexander Berchansky at 11:49, 23 May 2021

2021-05-23T11:49:36Z

←Older revision		Revision as of 11:49, 23 May 2021
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	F: C-terminal domain		F: C-terminal domain
	*[[Liver receptor homolog-1]]?		*[[Liver receptor homolog-1]]?
		+	The <scene name='77/777031/Cv/2'>ligand of LRH-1 binds deep in the binding pocket and is fully engulfed by it</scene>.

		+	<scene name='77/777031/Cv/4'>Agonist binding site</scene>.
	==Endoplasmic reticulum/Sarcoplasmic reticulum receptors==		==Endoplasmic reticulum/Sarcoplasmic reticulum receptors==

Alexander Berchansky at 11:48, 23 May 2021

2021-05-23T11:48:10Z

←Older revision		Revision as of 11:48, 23 May 2021
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	The structure of the complex of the ligand-binding domain of PR with RU486 - an abortion-inducing drug - shows the ligand bound at a similar location to other agonists or partial agonists with a flexible loop of PR being a possible entry route to the <scene name='78/780972/Cv/4'>binding site and several PR-RU486 interactions</scene>		The structure of the complex of the ligand-binding domain of PR with RU486 - an abortion-inducing drug - shows the ligand bound at a similar location to other agonists or partial agonists with a flexible loop of PR being a possible entry route to the <scene name='78/780972/Cv/4'>binding site and several PR-RU486 interactions</scene>
	*[[Androgen receptor]]		*[[Androgen receptor]]
		+	AR structure is composed of 5 domains:
		+	A/B: N-terminal regulatory domain contains activation function 1 (residues 101-370), activation function 5 (residues 360-485) and dimerization surface (residues 1-36 and 370-494).
		+
		+	C: DNA binding domain (DBD)
		+
		+	D: Hinge region between DBD and LBD
		+
		+	E: Ligand binding domain (LBD) containing an <scene name='54/543362/Cv/3'>active site</scene> which binds intramolecularly the N-terminal FXXFL motif or coactivators with the same motif.
		+
		+	F: C-terminal domain
	*[[Liver receptor homolog-1]]?		*[[Liver receptor homolog-1]]?

Alexander Berchansky at 11:45, 23 May 2021

2021-05-23T11:45:25Z

←Older revision		Revision as of 11:45, 23 May 2021
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	{{Template:ColorKey_Turn}}). <scene name='78/781019/Cv/7'>It forms hydrogen bonds with 4 MR residues</scene><ref>PMID:15967794</ref>. <scene name='78/781019/Cv/8'>Whole binding site</scene>. Water molecules are shown as red spheres.		{{Template:ColorKey_Turn}}). <scene name='78/781019/Cv/7'>It forms hydrogen bonds with 4 MR residues</scene><ref>PMID:15967794</ref>. <scene name='78/781019/Cv/8'>Whole binding site</scene>. Water molecules are shown as red spheres.
	*[[Progesterone receptor]]		*[[Progesterone receptor]]
		+	The structure of the complex of the ligand-binding domain of PR with RU486 - an abortion-inducing drug - shows the ligand bound at a similar location to other agonists or partial agonists with a flexible loop of PR being a possible entry route to the <scene name='78/780972/Cv/4'>binding site and several PR-RU486 interactions</scene>
	*[[Androgen receptor]]		*[[Androgen receptor]]
	*[[Liver receptor homolog-1]]?		*[[Liver receptor homolog-1]]?

Alexander Berchansky at 11:43, 23 May 2021

2021-05-23T11:43:25Z

←Older revision		Revision as of 11:43, 23 May 2021
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	Structure of estradiol metal chelate and estrogen receptor complex: The basis for designing a new class of SERMs<ref>PMID: 21473635</ref>.		Structure of estradiol metal chelate and estrogen receptor complex: The basis for designing a new class of SERMs<ref>PMID: 21473635</ref>.
-	Selective estrogen receptor modulators, such as estradiol 17-derived metal complexes, have been synthesized as targeted probes for the diagnosis and treatment of breast cancer. ~~Here, we report the~~ detailed 3D structure of <scene name='Journal:JMEDCHEM:1/Cv/11'>estrogen receptor ~~alpha~~ ligand-binding domain (ER-LBD)</scene> bound with a novel <scene name='Journal:JMEDCHEM:1/Cv/5'>estradiol-derived metal complex, estradiol-pyridinium tetra acetate europium (III) (EPTA-Eu)</scene> at 2.6Å resolution (~~PDB ID '''~~[[2yat]]~~'''~~). The residues <scene name='Journal:JMEDCHEM:1/Cv/10'>Glu353, Arg394 and His524 and the conserved water molecule (W1006) form hydrogen bonds</scene> with EPTA-Eu. The hydrogen bonds are shown as white dashed lines. <scene name='Journal:JMEDCHEM:1/Cv/7'>Superposition</scene> of this structure with the structure of native ligand 17β-estradiol (E2) in the complex of E2/ERα-LBD complex (~~'''~~[[1ere]]~~'''~~) reveals that the <scene name='Journal:JMEDCHEM:1/Cv/12'>E2 core of EPTA-Eu overlaps closely with that of E2 itself</scene>. The <scene name='Journal:JMEDCHEM:1/Cv/9'>hydrogen bonds network</scene> made by additional estrogen receptor residues (''e.g.'' Glu419 of H7 and Glu339 of H3, this depends on subunit), may work together with the E2 17β hydroxyl-His524 hydrogen bond and tighten the neck of the LBP upon binding of the endogenous ligand E2. 4-Hydroxytamoxifen (OHT) is an other selective estrogen receptor modulator. <scene name='Journal:JMEDCHEM:1/Al/5'>Superposition</scene> of EPTA-Eu/ERα-LBD complex on OHT/ERα-LBD complex (~~'''~~[[3ert]]~~'''~~) shows that there is similar network of hydrogen bonds in both complexes, except for His524 which does not form hydrogen bond with OHT in the OHT/ERα-LBD complex. <scene name='Journal:JMEDCHEM:1/Al1/3'>Superposition of structures of all these three complexes:</scene> E2/ERα-LBD (~~'''~~[[1ere]]~~'''~~), OHT/ERα-LBD (~~'''~~[[3ert]]~~'''~~) and EPTA-Eu/ERα-LBD shows that they overlap well in the majority portions of the domain, but differ significantly in the region of the 'omega loop'. They display different synergistic reciprocating movements, depending on the specific nature of the ligand bound. The structure of estrogen receptor complexed with EPTA-Eu provides important information pertinent to the design of novel functional ER targeted probes for clinical applications.	+	Selective estrogen receptor modulators, such as estradiol 17-derived metal complexes, have been synthesized as targeted probes for the diagnosis and treatment of breast cancer. The detailed 3D structure of <scene name='Journal:JMEDCHEM:1/Cv/11'>estrogen receptor α ligand-binding domain (ER-LBD)</scene> bound with a novel <scene name='Journal:JMEDCHEM:1/Cv/5'>estradiol-derived metal complex, estradiol-pyridinium tetra acetate europium (III) (EPTA-Eu)</scene> at 2.6Å resolution was reported ([[2yat]]). The residues <scene name='Journal:JMEDCHEM:1/Cv/10'>Glu353, Arg394 and His524 and the conserved water molecule (W1006) form hydrogen bonds</scene> with EPTA-Eu. The hydrogen bonds are shown as white dashed lines. <scene name='Journal:JMEDCHEM:1/Cv/7'>Superposition</scene> of this structure with the structure of native ligand 17β-estradiol (E2) in the complex of E2/ERα-LBD complex ([[1ere]]) reveals that the <scene name='Journal:JMEDCHEM:1/Cv/12'>E2 core of EPTA-Eu overlaps closely with that of E2 itself</scene>. The <scene name='Journal:JMEDCHEM:1/Cv/9'>hydrogen bonds network</scene> made by additional estrogen receptor residues (''e.g.'' Glu419 of H7 and Glu339 of H3, this depends on subunit), may work together with the E2 17β hydroxyl-His524 hydrogen bond and tighten the neck of the LBP upon binding of the endogenous ligand E2. 4-Hydroxytamoxifen (OHT) is an other selective estrogen receptor modulator. <scene name='Journal:JMEDCHEM:1/Al/5'>Superposition</scene> of EPTA-Eu/ERα-LBD complex on OHT/ERα-LBD complex ([[3ert]]) shows that there is similar network of hydrogen bonds in both complexes, except for His524 which does not form hydrogen bond with OHT in the OHT/ERα-LBD complex. <scene name='Journal:JMEDCHEM:1/Al1/3'>Superposition of structures of all these three complexes:</scene> E2/ERα-LBD ([[1ere]]), OHT/ERα-LBD ([[3ert]]) and EPTA-Eu/ERα-LBD shows that they overlap well in the majority portions of the domain, but differ significantly in the region of the 'omega loop'. They display different synergistic reciprocating movements, depending on the specific nature of the ligand bound. The structure of estrogen receptor complexed with EPTA-Eu provides important information pertinent to the design of novel functional ER targeted probes for clinical applications.
	*[[Ivan Koutsopatriy estrogen receptor]]		*[[Ivan Koutsopatriy estrogen receptor]]
	ER is a modular protein composed of a ligand binding domain, a DNA binding domain and a transactivation domain. ER is a DNA-binding transcription factor.		ER is a modular protein composed of a ligand binding domain, a DNA binding domain and a transactivation domain. ER is a DNA-binding transcription factor.

Alexander Berchansky at 11:37, 23 May 2021

2021-05-23T11:37:46Z

←Older revision		Revision as of 11:37, 23 May 2021
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	*[[Glucocorticoid receptor]]		*[[Glucocorticoid receptor]]
	*[[Mineralocorticoid receptor]]		*[[Mineralocorticoid receptor]]
		+	The MR ligand aldosterone binds in a <scene name='78/781019/Cv/6'>fully enclosed pocket, contacting residues with six α-helices and a β-turn</scene> ({{Template:ColorKey_Helix}}, {{Template:ColorKey_Strand}}, {{Template:ColorKey_Loop}},
		+	{{Template:ColorKey_Turn}}). <scene name='78/781019/Cv/7'>It forms hydrogen bonds with 4 MR residues</scene><ref>PMID:15967794</ref>. <scene name='78/781019/Cv/8'>Whole binding site</scene>. Water molecules are shown as red spheres.
	*[[Progesterone receptor]]		*[[Progesterone receptor]]
	*[[Androgen receptor]]		*[[Androgen receptor]]

Alexander Berchansky at 11:35, 23 May 2021

2021-05-23T11:35:17Z

←Older revision		Revision as of 11:35, 23 May 2021
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	<scene name='54/545859/Cv/3'>Structure</scene> of human FXR ligand-binding domain (deeppink) complex with non-steroidal agonist, nuclear receptor coactivator 1 peptide (cyan) and sulfate ions ([[3ruu]]).		<scene name='54/545859/Cv/3'>Structure</scene> of human FXR ligand-binding domain (deeppink) complex with non-steroidal agonist, nuclear receptor coactivator 1 peptide (cyan) and sulfate ions ([[3ruu]]).
	*[[Vitamin D receptor]]		*[[Vitamin D receptor]]
-	<scene name='56/562378/Vit_d_receptor_3m7r/3'>Vitamin D receptor (VDR)</scene> is a transcription factor. Upon binding to vitamin D, VDR forms a heterodimer with retinoid-X receptor and binds to hormone response receptors on DNA causing gene expression. The <scene name='56/562378/Vit_d_receptor_ligand/1'>vitamin D hormone</scene> (in green) binds to receptors in its target cells, controlling the synthesis of many different proteins involved in ~~calcium~~ transport and utilization. <scene name='51/517370/Cv/2'>Vitamin D hormone binding site</scene>. <scene name='51/517370/Cv/3'>Vitamin D hormone is located in deep pocket</scene>. VDR contains two domains: a <scene name='56/562378/Lbd/1'>ligand binding domain (LBD)</scene>, that binds to the hormone (grey) and <scene name='56/562378/Dbd/2'>DNA-binding domain (DBD)</scene> that binds to DNA (green and blue are 2 same VDR structures). It pairs up with a similar protein, 9-cis retinoic acid receptor (RXR), and together they bind to the DNA, activating synthesis in some cases and repressing it in others.	+	<scene name='56/562378/Vit_d_receptor_3m7r/3'>Vitamin D receptor (VDR)</scene> is a transcription factor. Upon binding to vitamin D, VDR forms a heterodimer with retinoid-X receptor and binds to hormone response receptors on DNA causing gene expression. The <scene name='56/562378/Vit_d_receptor_ligand/1'>vitamin D hormone</scene> (green) binds to receptors in its target cells, controlling the synthesis of many different proteins involved in Ca transport and utilization.
		+
		+	<scene name='51/517370/Cv/2'>Vitamin D hormone binding site</scene>.

-	~~When~~ <scene name='56/~~562378~~/~~Serine_final~~/1'>~~serine~~</scene> ~~is mutated it is replaced with~~ a <scene name='56/562378/~~Glycine_final~~/1'>~~glycine~~</scene> ~~which results in an inhibition of transcriptional activation. When transcription is inhibited it results in p53 accumulation~~, ~~which activates~~ and ~~promotes p53 translocation into mitochondria leading~~ to ~~apoptosis. Transcription inhibition is useful in cancer patients~~ and ~~so can be used as treatment option. These~~ are ~~the outcomes of the mutation,~~ with ~~the research still in the process~~ to ~~find~~ the ~~potential cure for tumors~~.	+	<scene name='51/517370/Cv/3'>Vitamin D hormone is located in deep pocket</scene>. VDR contains 2 domains: a <scene name='56/562378/Lbd/1'>ligand binding domain (LBD)</scene>, that binds to the hormone (grey) and <scene name='56/562378/Dbd/2'>DNA-binding domain (DBD)</scene> that binds to DNA (green and blue are 2 same VDR structures). It pairs up with a similar protein, 9-cis retinoic acid receptor (RXR), and together they bind to the DNA, activating synthesis in some cases and repressing it in others.

-	<scene name='56/562378/Serine_final/1'>Serine</scene> is replaced with <scene name='56/562378/Asparticacid_final/1'>aspartic acid</scene> when mutated creating a negative charge. The negative charge at the residue inhibits DNA binding which cause a down – regulation of VDR activity. VDR needs DNA binding in order for it to be activated which is only possible with a serine residue. ~~Research~~ is ~~still continuing to find~~ a ~~therapeutic cause for~~ this ~~mutation~~.	+	When <scene name='56/562378/Serine_final/1'>serine</scene> is mutated it is replaced with a <scene name='56/562378/Glycine_final/1'>glycine</scene> which results in an inhibition of transcriptional activation. When transcription is inhibited it results in p53 accumulation, which activates and promotes p53 translocation into mitochondria leading to apoptosis. Transcription inhibition is useful in cancer patients and so can be used as treatment option.
		+
		+	<scene name='56/562378/Serine_final/1'>Serine</scene> is replaced with <scene name='56/562378/Asparticacid_final/1'>aspartic acid</scene> when mutated creating a negative charge. The negative charge at the residue inhibits DNA binding which cause a down – regulation of VDR activity. VDR needs DNA binding in order for it to be activated which is only possible with a serine residue.
		+
		+	The vitamin D nuclear receptor is a ligand-dependent transcription factor that controls multiple biological responses such as cell proliferation, immune responses, and bone mineralization. Numerous 1 α,25(OH)(2)D(3) analogues, which exhibit low calcemic side effects and/or antitumoral properties, have been synthesized. It was shown that <scene name='56/562378/3a3z/1'>the synthetic analogue (20S,23S)-epoxymethano-1α,25-dihydroxyvitamin D(3) (2a)</scene> acts as a 1α,25(OH)(2)D(3) superagonist and exhibits both antiproliferative and prodifferentiating properties in vitro. Using this information and on the basis of the crystal structures of human VDR ligand binding domain (hVDR LBD) bound to 1α,25(OH)(2)D(3), 2α-methyl-1α,25(OH)(2)D(3), or 2a, a novel analogue, 2α-methyl-(20S,23S)-epoxymethano-1α,25-dihydroxyvitamin D(3) (4a) was designed, in order to increase its transactivation potency.

-	The vitamin D nuclear receptor is a ligand-dependent transcription factor that controls multiple biological responses such as cell proliferation, immune responses, and bone mineralization. Numerous 1 alpha,25(OH)(2)D(3) analogues, which exhibit low calcemic side effects and/or antitumoral properties, have been synthesized. In the article, "Structure-function relationships and crystal structures of the vitamin D receptor bound 2 alpha-methyl-(20S,23S)- and 2 alpha-methyl-(20S,23R)-epoxymethano-1 alpha,25-dihydroxyvitamin D3" by Antony, P. et al, they showed that <scene name='56/562378/3a3z/1'>the synthetic analogue (20S,23S)-epoxymethano-1alpha,25-dihydroxyvitamin D(3) (2a)</scene> acts as a 1alpha,25(OH)(2)D(3) superagonist and exhibits both antiproliferative and prodifferentiating properties in vitro. Using this information and on the basis of the crystal structures of human VDR ligand binding domain (hVDR LBD) bound to 1alpha,25(OH)(2)D(3), 2alpha-methyl-1alpha,25(OH)(2)D(3), or 2a, we designed a novel analogue, 2alpha-methyl-(20S,23S)-epoxymethano-1alpha,25-dihydroxyvitamin D(3) (4a), in order to increase its transactivation potency. Here, we solved the crystal structures of the hVDR LBD in complex with the 4a (C23S) and its epimer 4b (C23R) and determined their correlation with specific biological outcomes.
	*[[Pregnane X receptor]]		*[[Pregnane X receptor]]
	<scene name='57/571285/Cv/3'>PXR ligand-binding pocket is flexible and allows binding to structurally and chemically distinct ligands among them the macrolide antibiotic rifampicin</scene> which is used in testing tuberculosis.		<scene name='57/571285/Cv/3'>PXR ligand-binding pocket is flexible and allows binding to structurally and chemically distinct ligands among them the macrolide antibiotic rifampicin</scene> which is used in testing tuberculosis.

←Older revision		Revision as of 13:27, 23 May 2021
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	* [[Tamoxifen\|Tamoxifen and the Estrogen receptor]]		* [[Tamoxifen\|Tamoxifen and the Estrogen receptor]]
	* [[Student Project 10 for UMass Chemistry 423 Spring 2015]]		* [[Student Project 10 for UMass Chemistry 423 Spring 2015]]
-	<scene name='48/483891/Initial_view/1'>Estrogen receptor β</scene> (ER-β) is ~~one~~ of the 2 isoforms of the estrogen receptor, a ligand-activated transcription factor which regulates the biological effects of the steroid hormone 17 β-estradiol, or estrogen, in both males and females. The complex is a hetero-tetrameric assembly consisting of 4 molecules and a ligand: 2 copies of <scene name='48/483891/Erbeta/1'>estrogen receptor β</scene>, 2 copies of <scene name='48/483891/Steroid_receptor/3'>steroid receptor coactivator-1</scene>, and the ligand, <scene name='48/483891/Ligand/3'>Genistein</scene>. Once the ligand is bound, the complex recruits the steroid receptor coactivators, which recruit other proteins to form the transcriptional complex for initiation of transcription. This activates expression of reporter genes containing estrogen response elements. Genistein is a phytoestrogen with structural similarity to estrogen which competes for estrogen receptors.	+	<scene name='48/483891/Initial_view/1'>Estrogen receptor β</scene> (ER-β) is 1 of the 2 isoforms of the estrogen receptor, a ligand-activated transcription factor which regulates the biological effects of the steroid hormone 17 β-estradiol, or estrogen, in both males and females. The complex is a hetero-tetrameric assembly consisting of 4 molecules and a ligand: 2 copies of <scene name='48/483891/Erbeta/1'>estrogen receptor β</scene>, 2 copies of <scene name='48/483891/Steroid_receptor/3'>steroid receptor coactivator-1</scene>, and the ligand, <scene name='48/483891/Ligand/3'>Genistein</scene>. Once the ligand is bound, the complex recruits the steroid receptor coactivators, which recruit other proteins to form the transcriptional complex for initiation of transcription. This activates expression of reporter genes containing estrogen response elements. Genistein is a phytoestrogen with structural similarity to estrogen which competes for estrogen receptors.

	Although estrogen receptor β is widely expressed, it is not the primary estrogen receptor in most tissues. As a result, it has become a target for drug delivery, especially since it is 40x more selective for genistein than the α isoform. This enhanced selectivity may be caused by differences in residues <scene name='48/483891/Met336_ile373/2'>336 and 373</scene> between the 2 isoforms, allowing ER-β to accommodate more polar substituents in its binding pocket. ER-β differs greatly from ER-α at the N-terminal domains, which can be seen located at opposite ends from the C termini in this <scene name='48/483891/Rainbow/1'>rainbow representation</scene>. The protein is composed of 3 sections: a modulating N-terminal domain, a DNA-binding domain and a C-terminal ligand-binding domain.		Although estrogen receptor β is widely expressed, it is not the primary estrogen receptor in most tissues. As a result, it has become a target for drug delivery, especially since it is 40x more selective for genistein than the α isoform. This enhanced selectivity may be caused by differences in residues <scene name='48/483891/Met336_ile373/2'>336 and 373</scene> between the 2 isoforms, allowing ER-β to accommodate more polar substituents in its binding pocket. ER-β differs greatly from ER-α at the N-terminal domains, which can be seen located at opposite ends from the C termini in this <scene name='48/483891/Rainbow/1'>rainbow representation</scene>. The protein is composed of 3 sections: a modulating N-terminal domain, a DNA-binding domain and a C-terminal ligand-binding domain.
	{{Template:ColorKey_N2CRainbow}}		{{Template:ColorKey_N2CRainbow}}

-	Each ERβ contains several domains with specific functions: an N-terminal domain (NTD), a {{Template:ColorKey Composition DNA}}-binding domain (DBD), a flexible hinge region and a C-terminal {{Template:ColorKey Composition Ligand}}-binding domain (LBD). The complex overall is about <scene name='48/483891/Erhelices/1'>66% helical (10 helices; 160 residues) and 3% β-sheet (2 strands; 9 residues)</scene>.	+	Each ERβ contains several domains with specific functions: an N-terminal domain (NTD), a {{Template:ColorKey Composition DNA}}-binding domain (DBD), a flexible hinge region and a C-terminal {{Template:ColorKey Composition Ligand}}-binding domain (LBD). The complex overall is about <scene name='48/483891/Erhelices/1'>66% helical (10 helices; 160 residues) and 3% β-sheet (2 strands; 9 residues)</scene>. The <scene name='48/483891/Ntd-erbeta/2'>NTD</scene> is the 1st activation function (AF-1) domain that consists mostly of random coils and a small portion of helices (red) and sheets (green); it is a <scene name='48/483891/Sequence_conservation/1'>variable region</scene>. This lack of structure allows the region to recruit and bond many different interaction partners. This region also has the capacity to transactivate transcription without binding estrogen.
-		+
-	The <scene name='48/483891/Ntd-erbeta/2'>NTD</scene> is the 1st activation function (AF-1) domain that consists mostly of random coils and a small portion of helices (red) and sheets (green); it is a <scene name='48/483891/Sequence_conservation/1'>variable region</scene>. This lack of structure allows the region to recruit and bond many different interaction partners. This region also has the capacity to transactivate transcription without binding estrogen.	+

	{{Template:ColorKey_ConSurf_NoYellow}}		{{Template:ColorKey_ConSurf_NoYellow}}
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	Binding at the LBD activates transcription mediated by the DBD. This domain is entirely helical; the LBD interacts with genistein through helices. The conformationally dynamic portion of this region gives rise to ERβ’s ligand-dependent transcriptional activation (AF-2) function. A key element of AF-2 is helix 12 (H12), which acts as a conformational switch; different receptor ligands influence the orientation of H12. Agonist ligands like genistein position H12 across the ligand-binding pocket of the LBD, which provides a coactivator docking surface. Geinstein binding allows the helices of AF-2 to form a shallow hydrophobic binding site for leucine-rich motifs of coactivators to bind. This conformation provides optimal interaction with coactivators and transcription is activated.		Binding at the LBD activates transcription mediated by the DBD. This domain is entirely helical; the LBD interacts with genistein through helices. The conformationally dynamic portion of this region gives rise to ERβ’s ligand-dependent transcriptional activation (AF-2) function. A key element of AF-2 is helix 12 (H12), which acts as a conformational switch; different receptor ligands influence the orientation of H12. Agonist ligands like genistein position H12 across the ligand-binding pocket of the LBD, which provides a coactivator docking surface. Geinstein binding allows the helices of AF-2 to form a shallow hydrophobic binding site for leucine-rich motifs of coactivators to bind. This conformation provides optimal interaction with coactivators and transcription is activated.

-	Genistein's bicyclic form allows it to hydrogen bond on opposite sides with the hydroxyls of the histidine groups on the receptor. <scene name='48/483891/Estrogen_kyle/12'>His475's</scene> binding to the receptor causes a conformational change and activates the receptor resulting in up-regulation for coactivators. Down-regulation will occur in the presence of corepressor as they bind to repressors and indirectly regulate gene expression. In order for the estrogen receptor β genistein to bind to a receptor and activate it there must be stabilization by a coactivator. The coactivator increases the gene expression and with this increase allows it to bind to an activator group consisting of a DNA binding domain. The estrogen receptor is found to be comprised of a dimer attached to a ligand and coactivator peptide which helps to stabilize the structure of each monomer. The conformational state of helix-12 can be modified by the binding of the coactivator.	+	Genistein's bicyclic form allows it to hydrogen bond on opposite sides with the hydroxyls of the histidine groups on the receptor. <scene name='48/483891/Estrogen_kyle/12'>His475's</scene> binding to the receptor causes a conformational change and activates the receptor resulting in up-regulation for coactivators. Down-regulation will occur in the presence of corepressor as they bind to repressors and indirectly regulate gene expression. In order for the estrogen receptor β genistein to bind to a receptor and activate it there must be stabilization by a coactivator. The coactivator increases the gene expression and with this increase allows it to bind to an activator group consisting of a DNA binding domain. The estrogen receptor is found to be comprised of a dimer attached to a ligand and coactivator peptide which helps to stabilize the structure of each monomer. The conformational state of helix-12 can be modified by the binding of the coactivator.

	This <scene name='48/483891/Estrogen_kyle/8'>scene</scene> depicts the hydrophobic and hydrophilic residues of the estrogen receptor. The hydrophobic regions are primarily on the inside of the protein surrounding genistein (red). Having the hydrophobic residues surrounding the binding pocket will stabilize the structure. The structure of this pocket is tertiary and do to the hydrophobic interactions inside the pocket and hydrophilic interactions on the outside help to stabilize this tertiary structure. The <scene name='48/483891/Estrogen_kyle/16'>binding pocket</scene> is hydrophobic which means that an increase in lipophilicity would increase the affinity for ligands which in this case is genistein. The genistein structure has 3 hydroxyl groups, an ether and an ester. These 3 functional groups are polar and have many possibilities for hydrogen bonding. The His475 and Met336 residues in the binding pocket are capable of forming hydrogen bonds with genistein do to the many hydrogen bond forming functional groups. These residues are different from the residues found in ERα and so the selectivity of genistein is much greater for ERβ.		This <scene name='48/483891/Estrogen_kyle/8'>scene</scene> depicts the hydrophobic and hydrophilic residues of the estrogen receptor. The hydrophobic regions are primarily on the inside of the protein surrounding genistein (red). Having the hydrophobic residues surrounding the binding pocket will stabilize the structure. The structure of this pocket is tertiary and do to the hydrophobic interactions inside the pocket and hydrophilic interactions on the outside help to stabilize this tertiary structure. The <scene name='48/483891/Estrogen_kyle/16'>binding pocket</scene> is hydrophobic which means that an increase in lipophilicity would increase the affinity for ligands which in this case is genistein. The genistein structure has 3 hydroxyl groups, an ether and an ester. These 3 functional groups are polar and have many possibilities for hydrogen bonding. The His475 and Met336 residues in the binding pocket are capable of forming hydrogen bonds with genistein do to the many hydrogen bond forming functional groups. These residues are different from the residues found in ERα and so the selectivity of genistein is much greater for ERβ.

-	~~We can see the initial view of the complex.~~ Upon visualizing the estrogen receptor in an ~~arrow formation,~~ <scene name='48/483891/Arrow_view/1'>arrow representation</scene>, the structure can be classified as parallel or anti-parallel. Here is the zoomed <scene name='48/483891/Hydrophobic_pocket/3'>primarily hydrophobic pocket</scene>.	+	Upon visualizing the estrogen receptor in an <scene name='48/483891/Arrow_view/1'>arrow representation</scene>, the structure can be classified as parallel or anti-parallel. Here is the zoomed <scene name='48/483891/Hydrophobic_pocket/3'>primarily hydrophobic pocket</scene>.
	*[[Estrogen-related receptor]]		*[[Estrogen-related receptor]]
	<scene name='50/501401/Cv/4'>Binding of nuclear receptor corepressor 2 peptide and 4-hydroxytamoxifen</scene> to human estrogen-related receptor γ. The chemotherapeutic drugs bisphenol and <scene name='50/501401/Cv/5'>tamoxifen</scene> are nestled between 4 alpha helices in the ERR active site.		<scene name='50/501401/Cv/4'>Binding of nuclear receptor corepressor 2 peptide and 4-hydroxytamoxifen</scene> to human estrogen-related receptor γ. The chemotherapeutic drugs bisphenol and <scene name='50/501401/Cv/5'>tamoxifen</scene> are nestled between 4 alpha helices in the ERR active site.