Estrogen receptor estradiol interactions with

Estrogens act by interacting with the specific estradiol receptors in the cytoplasm of the target cells and mediate the transcription of the relevant mRNA by attaching itself to the appropriate gene. 

The biological activities of steroid hormones result from interactions with specific receptors. For example, estradiol interacts with the estrogen receptor. Some industrial chemicals, such as DDT, bisphenol A, and polychlorinated biphenyls, may possibly interact with these receptors and cause hormonal effects on people and wildlife. 

Estradiol (E2) (7, Figure 5) is the most potent natural steroid. It contains two hydroxy functions one in the phenolic 3 position and one in the 17 position. With these synthetic handles, three possible CDSs can be designed attaching the targetor at the 17-, at the 3-, or at both positions. Attachment at either position, but especially at the 17 position, should greatly decrease the pharmacological activity of E2, because these esters are known not to interact with estrogen receptors [114],... 

Figure 31.25. Coactivator-Nuclear Hormoue Receptor Interactions. The structure of a complex between the ligand-binding domain of the estrogen receptor with estradiol bound and a peptide from a coactivator reveals that the Leu-X-X-Leu-Leu (LXXLL) sequence forms a helix that binds in a groove on the surface of the ligand-binding domain.

L. Janocko, J. M. Lamer, and R. B. Hochberg, The interaction of C-17 esters of estradiol with the estrogen receptor, Endocrinology 774 1180 (1984). 

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