Two excelent 3D animations about the mechanism of action of estradiol in the activation of estradiol receptor.
Additional information from Wikipedia article on estrogen receptor:
“There are two types of estrogen receptor, ER is a member of the nuclear hormone family of intracellular receptors which is activated by the hormone 17β-estradiol (estrogen), while the estrogen (G protein coupled) receptor GPER is a G-protein coupled receptor. This article refers to the nuclear hormone receptor ER.
The main function of the estrogen receptor is as a DNA binding transcription factor which regulates gene expression. However the estrogen receptor also has additional functions independent of DNA binding. “