The alcR gene of Aspergillus nidulans encodes a protein with a zinc
finger motif, the AlcR activator protein/ AlcR transactivator. In
the presence of ethanol, AlcR specifically binds DNA motifs of the
ethanol regulon of A.nidulans, inducing the expression of the genes
of this regulon. This ethanol pathway is a highly inducible gene
system, the so-called alc system, responsible for the utilization
of ethanol as sole source of carbon in A.nidulans.