Abstract
A considerable number of prokaryotic transcription factors belong to the LysR family. By comparison with the amino acid sequence of the putative DNA-binding domain (DBD) of BirA, for which the crystal structure has been determined, we predict that the LysR DBD has three α -helices and three β-strands, and that the third α-helix binds to DNA. Contacts between DNA bases and amino acid residues in the predicted recognition helix are discussed in comparison with those found in crystal structures of DNA-transcription factor complexes.