NMR solution structure of a AlcR(1-60)-DNA complex: Minor groove recognition by the N-terminus

Aspergillus nidulans is a filamentous fungus able to use ethanol as sole en ergy source. The activation of the ethanol regulon genes expression is medi ated by the AlcR protein. Its DNA-binding domain is located in the N-termin us (residues 1 to 60), and its NMR solution structure shows a global zinc b inuelear cluster fold, with two helices in addition to the basic binuclear motif. A small number of crystallographic structures of DNA complexes of binuclear cluster proteins is yet known, and points out the major groove and the fir st helix as the principal sites of interaction on the DNA and the protein r espectively. In this article we show evidences that the N-terminus of the p rotein is involved in binding to the minor groove.