The solution structure of a leucine-zipper motif peptide. Prot Engineer

'To whom correspondence should be addressed We report the complete structure determination of a 34 residue synthetic peptide with the amino acid sequence of the dimerization domain (leucine zipper) of GCN4. A high resolution structure in solution was obtained by 'H-NMR studies and distance geometry calculations followed by restrained energy minimization. A set of 20 final structures was obtained with an average root mean square deviation of 1.3 A for the backbone atoms (excluding the first and the last two residues). The structure contains an uninterrupted helix. A comparison with a structure previously determined for a larger peptide containing both the DNA-binding region (basic region) and the leucine-zipper motif shows the struc-tural independence of the leucine-zipper domain from the contiguous DNA binding region. Key words: DNA binding proteins/GCN4 protein/leucine zipper/ NMR structur