DNA-binding domain of estrogen receptors (ER) is composed of two C4-type zinc fingers
DNA-binding domain of estrogen receptors (ER) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which coordinates a single zinc atom. ER interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. Estrogen receptor is a transcription regulator that mediates the biological effects of hormone estrogen. The binding of estrogen to the receptor triggers the dimerization and the binding of the receptor dimer to estrogen response element, which is a palindromic inverted repeat: 5'GGTCAnnnTGACC-3', of target genes. Through ER, estrogen regulates development, reproduction and homeostasis. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, ER has a central well-conserved DNA binding domain (DBD), a variable N-terminal domain, a non-conserved hinge and a C-terminal ligand binding domain (LBD).