Mutational analysis reveals a dual role of Mdm2 acidic domain in the regulation of p53 stability

► We performed systematic mutational analysis of Mdm2 acidic domain. ► Two separate regions involved in p53 degradation were identified. ► Only one of the regions is required for p53 ubiquitylation. ► The other plays a role in a post-ubiquitylation step required for p53 degradation.