Biological Assembly 1  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Cyclic - C2  (3D View)
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly 2  

 3D View: Structure | 1D-3D View | Electron Density | Validation Report | Ligand Interaction

Global Symmetry: Dihedral - D4  (3D View)
Global Stoichiometry: Homo 8-mer - A8 

Biological assembly 2 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 57.04 kDa 
• Atom Count: 3717 
• Modelled Residue Count: 450 
• Deposited Residue Count: 492 
• Unique protein chains: 1

2FSZ

A second binding site for hydroxytamoxifen within the coactivator-binding groove of estrogen receptor beta

• PDB DOI: 10.2210/pdb2FSZ/pdb

• Classification: HORMONE/GROWTH FACTOR
• Organism(s): Homo sapiens
• Expression System: Escherichia coli BL21(DE3)
• Mutation(s): Yes 


• Deposited: 2006-01-23 Released: 2006-07-11 
• Deposition Author(s): Wang, Y.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 2.20 Å
• R-Value Free: 0.299 
• R-Value Work: 0.273 
• R-Value Observed: 0.274 

Literature

A second binding site for hydroxytamoxifen within the coactivator-binding groove of estrogen receptor beta

Wang, Y., Chirgadze, N.Y., Briggs, S.L., Khan, S., Jensen, E.V., Burris, T.P.

(2006) Proc Natl Acad Sci U S A 103: 9908-9911

• PubMed: 16782818 
• DOI: 10.1073/pnas.0510596103
• Primary Citation of Related Structures:  
  2FSZ


• PubMed Abstract: 
  

Evidence is presented that the estrogen antagonist 4-hydroxytamoxifen (HT) can occupy not only the core binding pocket within the ligand-binding domain of estrogen receptor (ER) beta but also a second site on its surface. The crystal structure of the ligand-binding domain (LBD) associated with HT was determined to 2.2 A and revealed two molecules of HT bound to the protein. One was located in the consensus ligand-binding pocket, whereas the other bound to a site that overlaps with the hydrophobic groove of the coactivator recognition surface. Relative to the ERalpha-tamoxifen structure, helix 12 has been displaced from the coactivator recognition surface and occupies a unique position. Although it has been demonstrated that association of the antagonist with the core ligand-binding pocket is sufficient to induce an antagonist ligand-binding domain conformation, this structure suggests that small molecules may directly antagonize receptor-coactivator interactions. These results provide a direct demonstration of two binding sites for HT in ERbeta, as has been previously suggested for ERalpha by using biochemical methods, and represent a crystal structure of a small nonpeptide molecule occupying the coactivator recognition site.

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Organizational Affiliation: 

Lilly Research Laboratories, Indianapolis, IN 46285, USA.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
Estrogen receptor beta	A, B	246	Homo sapiens	Mutation(s): 3  Gene Names: ESR2, ESTRB, NR3A2
UniProt & NIH Common Fund Data Resources
Find proteins for Q92731 (Homo sapiens) Explore Q92731  Go to UniProtKB:  Q92731
PHAROS:  Q92731 GTEx:  ENSG00000140009

Small Molecules

Ligands 1 Unique
ID	Chains	Name / Formula / InChI Key	2D Diagram
OHT	C [auth A], D [auth A], E [auth B], F [auth B]	4-HYDROXYTAMOXIFEN C26 H29 N O2 TXUZVZSFRXZGTL-QPLCGJKRSA-N

Binding Affinity Annotations
ID	Source	Binding Affinity
OHT	BindingDB:  2FSZ	Ki: min: 0.01, max: 1.7 (nM) from 4 assay(s)
		IC50: min: 2.6, max: 100 (nM) from 4 assay(s)
		EC50: min: 6, max: 32 (nM) from 2 assay(s)

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 2.20 Å
• R-Value Free: 0.299 
• R-Value Work: 0.273 
• R-Value Observed: 0.274 
• Space Group: I 4

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 105.04	α = 90
b = 105.04	β = 90
c = 102.391	γ = 90

Software Package:

Software Name	Purpose
CNS	refinement
PDB_EXTRACT	data extraction
HKL-2000	data reduction
SCALEPACK	data scaling
AMoRE	phasing
CNX	refinement

Structure Validation

Entry History 

Deposition Data

• Deposited Date: 2006-01-23 
• Released Date: 2006-07-11 
Deposition Author(s): Wang, Y.

Revision History  

• Version 1.0: 2006-07-11
  Type: Initial release
  
• Version 1.1: 2008-05-01
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance
• Version 1.3: 2018-01-24
  Changes: Structure summary
• Version 1.4: 2021-10-20
  Changes: Database references, Derived calculations