The second DNA-binding domain (DBD) of the 2DBD nuclear receptor is composed of two C4-type zinc fingers
The second DNA-binding domain (DBD) of the 2DBD nuclear receptor (NR) 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. The proteins contain two DBDs in tandem, probably resulting from an ancient recombination event. The 2DBD-NRs are found only in flatworm species, mollusks and arthropods. Their biological function is unknown.