p53 and SV40 T antigen bind to the same region overlapping the conserved domain of the TATA-binding protein.

In this report we demonstrate that the cloned human TATA-binding protein (TBP) interacts with T antigen. TBP co-immunoprecipitates with T antigen when incubated with the T antigen-specific monoclonal antibody PAb419, and Protein-A agarose. Gel retention analysis with a radiolabeled TATA box-containing probe showed that the complex of TBP and T antigen can bind to the TATA box. Recently, p53 has also been shown to interact with TBP. Using TBP deletion mutants and co-immunoprecipitation experiments with p53 or T antigen, we show that both p53 and T antigen bind to the same region, amino acids 203-275, within the conserved C-terminal domain of TBP. Binding of p53 and T antigen to the same domain on TBP may lead to competition between the two proteins for transcriptional function.