Figure 1.

ERα structume. The functional domains ERα include the DNA binding domain (DBD), ligand binding domain (LBD), and two transcriptional activation functions (AF), the AF-1 ligand-independent activation function domain and the AF-2 ligand-dependent activation domain. The A/B domain, at the amino terminus of the protein, contains AF-1. The C domain binds to DNA motifs (EREs) at target genes. The D domain or hinge region contributes to DNA binding specificity and nuclear localization. The E domain or LBD interacts with estrogens or SERMs. At the C- terminus is the F domain.