DNA-Binding Domain b. Conserved 240 residue hormone binding site. Vitamin D c. Thyroxine d. GCN4 in yeast is protein synthesized in response to amino acid starvation. GCN4 coordinately activates more than 40 gene s of amino acid biosynthesis. Homodimers by leucine zippers have also been described.
Homeotic genes control the general architecture plan of the embryo of higher eukaryotes.
Many genes of the homeotic genes contain common recurring sequences called the homeo box 3.