Structure of the human Mdmx protein bound to the p53 tumor suppressor transactivation domain.

The Mdmx oncoprotein has only recently emerged as a critical-independent to Mdm2-regulator of p53 activation. We have determined the crystal structure of the N-terminal domain of human Mdmx bound to a 15-residue transactivation domain peptide of human p53. The structure shows why antagonists of the Mdm2 binding to p53 are ineffective in the Mdmx-p53 interaction.