Drosophila GCM (glial cell missing) is a novel DNA-binding protein that determines the fate of glial precursors from the neural default to glia. The GCM protein contains the functional domain that is essential for recognition of the upstream sequence of the repo gene. In the DNA-binding region of this GCM protein, there is a cysteine-rich region with which divalent metal ions such as Zn2+ must bind and other proteins belonging to the GCM family have a corresponding region. To obtain a more detailed insight into the structural and functional features of this DNA-binding region, we have determined the minimal DNA-binding domain and obtained inductively coupled plasma atomic emission spectra and 1H-15N, 1H-15N-13C and 113Cd2+ NMR spectra, with or without its specific DNA molecule. Considering the results, it was concluded that the minimal DNA-binding domain includes two Zn2+-binding sites, one of which is adjacent to the interface for DNA binding. Systematic mutational analyses of the conserved cysteine residues in the minimal DNA-binding domain revealed that one Zn2+-binding site is indispensable for stabilization of the higher order structure of this DNA-binding domain, but that the other is not.
All Science Journal Classification (ASJC) codes
- Molecular Biology