DNA-binding domain of the orphan nuclear receptor, nerve growth factor-induced-B
DNA-binding domain (DBD) of the orphan nuclear receptor, nerve growth factor-induced-B (NGFI-B) 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. NGFI-B interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. NGFI-B is a member of the nuclear-steroid receptor superfamily. NGFI-B is classified as an orphan receptor because no ligand has yet been identified. NGFI-B is an early immediate gene product of embryo development that is rapidly produced in response to a variety of cellular signals including nerve growth factor. It is involved in T-cell-mediated apoptosis, as well as neuronal differentiation and function. NGFI-B regulates transcription by binding to a specific DNA target upstream of its target genes and regulating the rate of transcriptional initiation. NGFI-B binds to the NGFI-B response element (NBRE) 5'-(A/T)AAAGGTCA as a monomer. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, NGFI-B has a central well-conserved DNA binding domain (DBD), a variable N-terminal domain, a flexible hinge and a C-terminal ligand binding domain (LBD).