One part of the domain contains a region that mediates sequence specific DNA binding properties and the leucine zipper that is required to hold together (dimerize) two DNA binding regions.

The DNA binding region comprises a number of basic amino acids such as arginine and lysine.

[1][2] bZIP transcription factors are found in all eukaryotes and form one of the largest families of dimerizing TFs.

[3] An evolutionary study from 2008 revealed that 4 bZIP genes were encoded by the genome of the most recent common ancestor of all plants.

[4] Interactions between bZIP transcription factors are numerous and complex [5][6][3] and play important roles in cancer development[7] in epithelial tissues, steroid hormone synthesis by cells of endocrine tissues,[8] factors affecting reproductive functions,[9] and several other phenomena that affect human health.