DISTINCT REGIONS OF CU(I)-CENTER-DOT-ACE1 CONTACT 2 SPATIALLY-RESOLVED DNA MAJOR GROOVE SITES

The interaction between the Cu(I). ACE1 (CuACE1) transcription factor and its DNA binding site in the yeast metallothionein gene was studied by systematically altering the DNA sequence through base substitution , modification, and deletions as well as by altering the protein struc ture through chemical modification. We show here that CuACE1 is compri sed of two distinct domains that contact DNA through minor groove inte ractions located between two major groove interaction sites. The minor groove interactions are shown to be critical for formation of a stabl e CuACE1 . DNA complex, The NH2-terminal segment of ACEI is shown to c ontact the 5'-most distal major groove site.