<prompt> Steroids act via nuclear receptors which interact with DNA throughHelix turn helixZinc finger motifHistidineLeucine zipper  <response>: Binding of transcription regulatory proteins to DNA is regulated by several motifs :Helix turn helixLeucine zipperZinc fingerBinding motif for steroid receptor family thyroid nuclear receptor family is a zinc finger.In proteins with zinc - finger motif, the binding site is repeated 2-9 times.Proteins with helix-turn-helix and leucine zipper motifs form symmetrical palindromes and their DNA binding sites are symmetrical palindromes.In leucine - zipper motif, there is a periodic repeat of a leucine residue at every 7th position 