SOLUTION STRUCTURE OF A ZINC DOMAIN CONSERVED IN YEAST COPPER-REGULATED TRANSCRIPTION FACTORS

The three dimensional structure of the N-terminal domain (residues 1-4 2) of the copper-responsive transcription factor Amt1 from Candida gla brata has been determined by two-dimensional H-1-correlated nuclear ma gnetic resonance (NMR) methods. The domain contains an array of zinc-b inding 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 segme nts 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.