CHIME EXERCISE

The structure below is an example of a Cys₄ zinc finger motif. On the structure, note the following characteristics:

• The "finger" consists of both an irregular loop and a helix

• The receptors bind as pairs to the DNA strand, each receptor recognizing 1/2 of a palindrome sequence on the DNA and then docking to one of these two "half-sites" on the DNA with the correct spacing in between each other

                                The first receptor unit recognizes the half-site, while the second unit then measures the spacing between the two dimers and causes the receptor dimerization

• This motif is similar in function to DNA recognition motifs of H-T-H motifs and Leu Zippers