p53 Family members p63 and p73 are SAM domain-containing proteins

Homologs of the tumor suppressor p53, called p63 and p73, have been identif ied. The p63 and p73 family members possess a domain structure similar to p 53, but contain variable C-terminal extensions. We find that some of the C- terminal extensions contain Sterile Alpha Motif (SAM) domains. SAM domains are protein modules that an involved in protein-protein interactions. Consi stent with this role, the C-terminal SAM domains of the p63 and p73 may reg ulate function by recruiting other protein effecters.