Figure 1.

Schematics of the estrogen receptor (ER)α and ERβ structural regions. Estrogen receptor α is composed of 595 amino acids, while ERβ contains 530 amino acids. The structurally distinct amino terminal A/B domains share a 17% amino‐acid identity between the ERs. The near‐identical central C region (97%) is the DNA‐binding domain. The flexible hinge, or D, domain (36%) contains a nuclear localization signal and links the C domain to the multifunctional carboxyl terminal (E) domain, which shows 56% amino‐acid homology between the ERs. The carboxyl‐terminal F domain shares an 18% amino‐acid identity. The ERs are dimers with or without the endogenous ligand, 17β‐estradiol, the binding of which induces conformational changes in the receptors. The figure is modified from Muyan, et al168