FIG. 4.

Effects of related small molecules on p53 DNA binding. (A) Portions of the NAD⁺ molecule were incubated with p53 and ³²P-hdm2. NAm, niacinamide; FAD, flavin adenine dinucleotide. (B) Nucleoside diphosphates were added as indicated to p53-³²P-hdm2 DNA. (C) Thiamine, TMP, or TDP was added to p53 DNA binding reactions. (D) Kinetic analysis of the dissociation of p53 from DNA in the presence of nucleotides as indicated. Nucleotides were added to p53-³²P-hdm2, and then excess unlabeled hdm2 was added at time zero. The amount of p53 remaining bound to ³²P-hdm2 at the indicated times is plotted. (E) The effect of NAD or TDP on p53 binding to p21 versus hdm2 DNA is quantified below each lane. NB and −p53 are as defined for Fig. 2.