The Zn2Cys6 DNA-binding domain has been identified by sequence homology in approximately forty fungal proteins, including the K. lactis LAC9 transcriptional activator. Using 1H NMR spectroscopy, we have determined the solution structure of a cadmium-substituted form of the LAC9 DNA-binding domain. We have complemented this approach by applying a series of 113Cd-1H NMR experiments, including several novel heteroTOCSY-based techniques. The DNA-binding domain forms a core of two α-helix/extended strand segments around the Cd2 binudear cluster, with a network of amide proton-cysteinyl Sγ hydrogen bonds stablizing the cluster. Comparison with other Zn2Cys6 domain structures provides insight into the common structural elements used in metal coordination and DNA binding.
ASJC Scopus subject areas
- Structural Biology