Figure 1. Schematic diagram of the PAX6 protein

The protein consists of a paired domain (PD) including the checkered alternatively spliced exon 5a; the homeodomain (HD),separated from the PD by a linker region; and the proline, serine, and threonine-rich transactivation domain (PST). The first three exons and most of the fourth exon constitute the 5'UTR; the 3'UTR is about 1 kb.The expanded paired domain includes α1- α3,denoting the NH-terminal subdomain αhelices, and α4-α6, C-terminal subdomain αhelices.