Fig. 1.

The evolution of p53. a Illustration of the roles and the main functional protein domains of proteins of the p53 family. Ancestral p53/p63/p73 has roles in development and embryonic differentiation, giving rise to three genes with distinct roles on cellular homeostasis and cancer (p53) and on epidermal (p63) and neural (p73) development. TAD: transactivation domain; DBD: DNA-binding domain; OD: oligomerization doamain; TID: transcription inhibition domain. The illustration of the domains has been prepared with the software DOG for the visualisation of protein domain structures. b Phylogenetic tree comparing the ancestral p53/p63/p73 protein from the pre-vertebrate Ciona intestinalis with the human proteins p53, p63 and p73. Both the full-length (I) and the partial N-terminal sequences (II) of the ancestral p53/p63/p73 protein show higher overall homology to p73 and p53 as compared to p63. The sequences were retrieved by the NCBI database: ancestral p53/63/73: (NP_001071796.1); p53 (BAC16799.1); p63 (AAB21139.1) and p73 (AAC61887.1). The aligned N-terminal sequences used in this analysis are the following: ancestral p53/63/73: (NP_001071796.1, aa 1–33); p53: (BAC16799.1, aa 1–36); p73: (AAC61887.1, aa 1–32); and p63: (AAB21139.1, aa 1–30). The alignments and the trees were prepared by the software found on phylogeny.fr [76]. The phylogenetic distances values are noted. The pdb file 2MWY was used for the modelling of the extended region SQETFSDLWLLPEN of p53, including the BOX-I motif FSDLWLL