1qkn

From Proteopedia

RAT OESTROGEN RECEPTOR BETA LIGAND-BINDING DOMAIN IN COMPLEX WITH ANTAGONIST RALOXIFENE

PDB ID 1qkn

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Structural highlights

1qkn is a 1 chain structure with sequence from Rattus norvegicus. 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

ESR2_RAT Binds estrogens with an affinity similar to that of ER-alpha, and activates expression of reporter genes containing estrogen response elements (ERE) in an estrogen-dependent manner. Isoform 3 and isoform 4 are unable to bind DNA and activate transcription due to the truncation of the DNA binding domain. Isoform 2 shows loss of ligand binding affinity and suppresses ER-alpha and ER-beta1 mediated transcriptional activation and may act as a dominant negative regulator of estrogen action.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

Oestrogens exert their physiological effects through two receptor subtypes. Here we report the three-dimensional structure of the oestrogen receptor beta isoform (ERbeta) ligand-binding domain (LBD) in the presence of the phyto-oestrogen genistein and the antagonist raloxifene. The overall structure of ERbeta-LBD is very similar to that previously reported for ERalpha. Each ligand interacts with a unique set of residues within the hormone-binding cavity and induces a distinct orientation in the AF-2 helix (H12). The bulky side chain of raloxifene protrudes from the cavity and physically prevents the alignment of H12 over the bound ligand. In contrast, genistein is completely buried within the hydrophobic core of the protein and binds in a manner similar to that observed for ER's endogenous hormone, 17beta-oestradiol. However, in the ERbeta-genistein complex, H12 does not adopt the distinctive 'agonist' position but, instead, lies in a similar orientation to that induced by ER antagonists. Such a sub-optimal alignment of the transactivation helix is consistent with genistein's partial agonist character in ERbeta and demonstrates how ER's transcriptional response to certain bound ligands is attenuated.

Structure of the ligand-binding domain of oestrogen receptor beta in the presence of a partial agonist and a full antagonist.,Pike AC, Brzozowski AM, Hubbard RE, Bonn T, Thorsell AG, Engstrom O, Ljunggren J, Gustafsson JA, Carlquist M EMBO J. 1999 Sep 1;18(17):4608-18. PMID:10469641^[1]

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

References

↑ Pike AC, Brzozowski AM, Hubbard RE, Bonn T, Thorsell AG, Engstrom O, Ljunggren J, Gustafsson JA, Carlquist M. Structure of the ligand-binding domain of oestrogen receptor beta in the presence of a partial agonist and a full antagonist. EMBO J. 1999 Sep 1;18(17):4608-18. PMID:10469641 doi:10.1093/emboj/18.17.4608