Proteins which have DNA binding domain in its structure is

Zinc finger: Two types of zinc finger have been repoed, called the C2H2 finger and the C4 finger. The C2H2 zinc finger is a loop of 12 amino acids with two cysteines and two histidines at the base of the loop that tetrahedrally coordinates a zinc ion The a-helix contains a number of conserved basic amino acids and interacts directly with the DNA, binding in the major groove of the double helix. Transcription factors that contain zinc fingers often contain several such motifs; usually at least three zinc fingers are needed for tight DNA binding of the protein. Indeed RNA polymerase III transcription factor contains nine zinc fingers! The SP1 transcription factor, which binds to the SP1 box, has three zinc fingers.