Table II. Binding of wild-type and mutant p53 core domain proteins to double-stranded gadd45 DNA.
| p53 core domaina | [p53]50% (nM)b |
|---|---|
| WT | 100 |
| T123A | 180 |
| V143A | 150 |
| H168Rc | 190 |
| G245S | 160 |
| R249S | >1000 |
| N239Y | 190 |
| N268D | 160 |
| V143A/N268D | 160 |
| G245S/N239Y | 130 |
| R249S/T123A | >1000 |
| R249S/H168R | 170 |
| R249S/T123A/H168R | 170 |
aMutants are indicated by the wild-type residue, followed by the sequence of the mutation. Cancer mutants are in bold.
bCalculation of p53 core domain that gives 50% binding to the DNA. The experiments were performed at 20°C in 50 mM Tris pH 7.2 in the presence of 5 mM DTT. The protein concentration ranged from 0.03 to 1.0 μM. Biotinylated double-stranded gadd 45 oligonucleotide was injected onto the streptavidin-coated chip, resulting in 400–800 response units (RU) immobilized. The data were fitted to the two-state transition curve equation using the program KALEIDAGRAPH and the best fit was used to calculate the DNA-binding activity.
cThis mutation is cancer associated according to the p53 database (http://www.iarc.fr), but in this study was used as a suppressor mutation.