The binding of the p53 transactivation domain by regulatory proteins regulates p53 transcription activation. This motif is comprised of a single amphipathic alpha helix and contains a highly conserved sequence [1-2].

1: Structure of the MDM2 oncoprotein bound to the p53 tumor suppressor transactivation domain. Kussie PH, Gorina S, Marechal V, Elenbaas B, Moreau J, Levine AJ, Pavletich NP; Science. 1996;274:948-953. PMID:8875929

2: Structural details on mdm2-p53 interaction. Chi SW, Lee SH, Kim DH, Ahn MJ, Kim JS, Woo JY, Torizawa T, Kainosho M, Han KH; J Biol Chem. 2005;280:38795-38802. PMID:16159876