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PDBsum entry 1err
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Nuclear receptor
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PDB id
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1err
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Molecular basis of agonism and antagonism in the oestrogen receptor.
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Authors
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A.M.Brzozowski,
A.C.Pike,
Z.Dauter,
R.E.Hubbard,
T.Bonn,
O.Engström,
L.Ohman,
G.L.Greene,
J.A.Gustafsson,
M.Carlquist.
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Ref.
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Nature, 1997,
389,
753-758.
[DOI no: ]
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PubMed id
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Abstract
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Oestrogens are involved in the growth, development and homeostasis of a number
of tissues. The physiological effects of these steroids are mediated by a
ligand-inducible nuclear transcription factor, the oestrogen receptor (ER).
Hormone binding to the ligand-binding domain (LBD) of the ER initiates a series
of molecular events culminating in the activation or repression of target genes.
Transcriptional regulation arises from the direct interaction of the ER with
components of the cellular transcription machinery. Here we report the crystal
structures of the LBD of ER in complex with the endogenous oestrogen,
17beta-oestradiol, and the selective antagonist raloxifene, at resolutions of
3.1 and 2.6 A, respectively. The structures provide a molecular basis for the
distinctive pharmacophore of the ER and its catholic binding properties. Agonist
and antagonist bind at the same site within the core of the LBD but demonstrate
different binding modes. In addition, each class of ligand induces a distinct
conformation in the transactivation domain of the LBD, providing structural
evidence of the mechanism of antagonism.
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Figure 2.
Figure 2 Agonist and antagonist binding modes. a, The 3.1-Å
resolution, six-fold averaged electron-density map (using model
phases) for the ER LBD-E[2] complex. b, The experimental, 2.6-Å
resolution electron-density map for the ER LBD-RAL complex after
DMMULTI multicrystal averaging. In both cases, the map is
contoured at 1  and
overlaid on the final refined models. c, d, Schematic
representation of the interactions made by E[2] (c) and RAL (d)
within the binding cavity. Residues that interact with ligand
and/or line the cavity are shown in theirapproximate positions.
Those that make direct hydrogen bonds are depictedin
ball-and-stick style with broken lines between the interacting
atoms.The hydrogen-bond distances shown are averaged between the
six (E[2]) or two (RAL) monomers. The atom names and ring
nomenclature of E[2] are also given.
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Figure 3.
Figure 3 Positioning of helix H12. Position is shown in a,
the ER LBD-E[2] complex; and b, the ER LBD-RAL complex. H12 is
drawn as a cylinder and coloured blue (E[2] complex) or green
(RAL complex). The remainder of the ER LBD is shown in red.
Dotted lines indicate unmodelled regions of the structures.
Hydrophobic residues located in the groove between H3 and H5
(yellow) and Lys 362 (K362, pink) are depicted in space-filling
form. The locations of Asp 538, Glu 542 and Asp 545 are
highlighted (brown spheres) along with the helices that interact
with H12 in the two complexes.
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The above figures are
reprinted
by permission from Macmillan Publishers Ltd:
Nature
(1997,
389,
753-758)
copyright 1997.
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