The first DNA-binding domain (DBD) of the 2DBD nuclear receptors is composed of two C4-type zinc fingers
The first DNA-binding domain (DBD) of the 2DBD nuclear receptors(NRs) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which co-ordinates a single zinc atom. NRs interact with specific DNA sites upstream of the target gene and modulate the rate of transcriptional initiation. Theses proteins contain two DBDs in tandem, probably resulted from an ancient recombination event. The 2DBD-NRs are found only in flatworm species, mollusks and arthropods. Their biological function is unknown.