Intracellular receptors: Difference between revisions
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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. 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. | ||
*[[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. <scene name='71/714947/Er_bound_to_dna/4'>ER bound to DNA </scene> The DNA binding domain can be clearly observed in this scene; the highlighted yellow helix in close proximity to the DNA is part of the DNA binding domain. The blue beta sheet close to the yellow DNA binding alpha helix is also part of the DNA binding domain. The transactivation domain forms an alpha helix which is colored in purple. The transactivation domain activates RNA polymerase when the receptor binds to DNA. The ligand binding domain may be observed here with the following scene.<scene name='71/714947/Agonist_ferutinine_bound_er/5'> Agonist ferutinine bound ER</scene> The ligand ferutinine (highlighted in pink) is bound by the ligand binding domain, composed of the blue colored alpha helices immediately surrounding the purple ligand. Another view of the ligand binding domain is shown here, with estradiol bound. <scene name='71/714947/Er_ligand_binding_domain_estra/1'>ER ligand binding domain bound to estradiol</scene>. | 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. | ||
<scene name='71/714947/Er_bound_to_dna/4'>ER bound to DNA</scene>. The DNA binding domain can be clearly observed in this scene; the highlighted yellow helix in close proximity to the DNA is part of the DNA binding domain. The blue beta sheet close to the yellow DNA binding alpha helix is also part of the DNA binding domain. The transactivation domain forms an alpha helix which is colored in purple. The transactivation domain activates RNA polymerase when the receptor binds to DNA. The ligand binding domain may be observed here with the following scene. | |||
<scene name='71/714947/Agonist_ferutinine_bound_er/5'>Agonist ferutinine bound ER</scene>. The ligand ferutinine (highlighted in pink) is bound by the ligand binding domain, composed of the blue colored alpha helices immediately surrounding the purple ligand. Another view of the ligand binding domain is shown here, with estradiol bound. <scene name='71/714947/Er_ligand_binding_domain_estra/1'>ER ligand binding domain bound to estradiol</scene>. | |||
* [[Estrogen receptor#Estrogen receptor α complexed with raloxifene and a corepressor peptide]] | * [[Estrogen receptor#Estrogen receptor α complexed with raloxifene and a corepressor peptide]] | ||
* [[Tamoxifen|Tamoxifen and the Estrogen receptor]] | * [[Tamoxifen|Tamoxifen and the Estrogen receptor]] |