FIGURE 5.

Modeling of p53 tetramer bound to nucleosomal DNA. A, shown is positioning of the p53RE decamers (AGGCATGCCT) in nucleosomes formed on the constructs p53Con30 and p53Con40. The p53 decamers (half-sites) are numbered d1–d4 in the direction 5′ to 3′. B, shown is the p53DBD tetramer interacting with the decamers d2 and d3 shown in A. The sequence-specific p53-DNA interactions are the same as in the co-crystal structure 2ATA (12); see main text for details. The p53 α-helices penetrate into the DNA major groove, whereas the α-helices of H3 histones interact with the minor groove; thus, there is no steric repulsion between the H3 and p53 α-helices.