Solution structure of a zinc domain conserved in yeast copper-regulated transcription factors

The three dimensional structure of the N-terminal domain (residues 1-42) of the copper-responsive transcription factor Amt1 from Candida glabrata has been determined by two-dimensional H-1-correlated nuclear magnetic resonance (NMR) methods. The domain contains an array of zinc-binding residues (Cys-X-2-Cys-X-8-Cys-X-His) that is conserved among a family of Cu-responsive transcription factors. The structure is unlike those of previously characterized zinc finger motifs, and consists of a three-stranded antiparallel beta-sheet with two short helical segments that project from one end of the beta-sheet. Conserved residues at positions 16, 18 and 19 form a basic patch that may be important for DNA binding.