NLS-binding and DNA-binding and dimerization domains of Nrf1
In Drosophila, the erect wing (ewg) protein is required for proper development of the central nervous system and the indirect flight muscles. The fly ewg gene encodes a novel DNA-binding domain that is also found in four genes previously identified in sea urchin, chicken, zebrafish, and human. Nuclear respiratory factor-1 is a transcriptional activator that has been implicated in the nuclear control of respiratory chain expression in vertebrates. The first 26 amino acids of nuclear respiratory factor-1 are required for the binding of dynein light chain. The interaction with dynein light chain is observed for both ewg and Nrf-1, transcription factors that are structurally and functionally similar between humans and Drosophila. The highest level of expression of both ewg and Nrf-1 was found in the central nervous system, somites, first branchial arch, optic vesicle, and otic vesicle. In the mouse Nrf-1 protein there is also an NLS domain at 88-116, and a DNA binding and dimerization domain at 127-282. Ewg is a site-specific transcriptional activator, and evolutionarily conserved regions of ewg contribute both positively and negatively to transcriptional activity.