Two distinct domains are found in Pax6 — a homeodomain and a paired domain. Recent interest has focused on the paired domain, mutations in which cause several human disorders, including aniridia. This figure depicts the structure as ribbons drawn through the main carbon backbone of the protein (red) and through the phosphate atoms of the DNA backbone (blue). Mutations in the paired domain interfere with the DNA-binding properties of Pax6, altering its function, and causing a detrimental effect on the health of an individual.

(Reproduced from Xu, H.E., Rould, M.A., Xu W., Epstein, J.A., Maas, R.L. and Pabo, C.O. (1999) 'Crystal structure of the human Pax6 paired domain-DNA complex reveals specific roles for the linker region and carboxy-terminal subdomain in DNA binding' Genes Dev. 13, 1263-1275, with permission.)