Fig. 2. Functional domains of p53 family proteins. The transactivation (TA), DNA binding (DBD), oligomerization (OD), SAM, and proline-rich (PR) domains are shown for each of the family members. Alternative splice p53 undergoes splicing, which results in a replacement of p53 amino acids 364390 with 17 unique amino acids. Alternative splicing of p73 and p63 mRNA (depicted in Fig. 1
) leads to different COOH termini. These forms are identical through the end of the OD region. Unique coding sequences are represented as different diagonal and vertical striped patterns. The Np73 and Np63 forms lack the TA domain and contain unique NH2-terminal amino acids (represented by the shaded N box) not found in the TA-containing forms. The asterisk located on p63 refers to a caspase recognition sequence, YVED. The entire SAM domain is present only in the forms of p73 and p63.