Analysis of the binding of p53 to DNAs containing mismatched and bulged bases. 
The tumor suppressor protein p53 modulates cellular response to DNA damage by a variety of mechanisms that may include direct recognition of some forms of primary DNA damage.  Linear 49-base pair duplex DNAs were constructed containing all possible single-base mismatches as well as a 3-cytosine bulge.  Filter binding and gel retardation assays revealed that the affinity of p53 for a number of these lesions was equal to or greater than that of the human mismatch repair complex, hMSH2-hMSH6, under the same binding conditions.  However, other mismatches including G/T, which is bound strongly by hMSH2-hMSH6, were poorly recognized by p53.  The general order of affinity of p53 was greatest for a 3-cytosine bulge followed by A/G and C/C mismatches, then C/T and G/T mismatches, and finally all the other mismatches.