The Estrogen Response Element
The Estrogen Response Element, as mentioned earlier, is palindromic, involving 2 six base pair regions separated by 3 base pairs. The consensus sequence of this is:
5-AGGTCAnnnTGACCT-3 (n=any nucleotide)
The location of this is in the major groove of the DNA.A helix from the protein, called the recgonition helix, slides into this groove to hydrogen bond with the DNA. The Glu25 residue hydrogen bonds to the cytosine33 of the DNA.
Here is a view of these all in combination.
This helix is held in this conformation by the zinc-binding motif, a structure found in those proteins with zinc-fingers.