DNA-binding domain of Drosophila ecdysone-induced protein 78 (E78) like is composed of two C4-type zinc fingers
DNA-binding domain of proteins similar to Drosophila ecdysone-induced protein 78 (E78) is composed of two C4-type zinc fingers. Each zinc finger contains a group of four Cys residues which coordinates a single zinc atom. E78 interacts with specific DNA sites upstream of the target gene and modulates the rate of transcriptional initiation. Drosophila ecdysone-induced protein 78 (E78) is a transcription factor belonging to the nuclear receptor superfamily. E78 is a product of the ecdysone-inducible gene found in an early late puff locus at position 78C during the onset of Drosophila metamorphosis. An E78 orthologue from the Platyhelminth Schistosoma mansoni (SmE78) has also been identified. It is the first E78 orthologue known outside of the molting animals--the Ecdysozoa. The SmE78 may be involved in transduction of an ecdysone signal in S. mansoni, consistent with its function in Drosophila. Like other members of the nuclear receptor (NR) superfamily of ligand-activated transcription factors, E78-like receptors have 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).