Biochemical investigation of protein/protein interactions involving acid-rich domains from transcription factors

In eukaryotic cells, transcription is regulated through a complex network of macromolecular interactions mediated by transcription factors, coactivators, and corepressors. To better understand how this network governs gene expression, it is critical to understand the precise details of the macromolecular interactions involved. The tumor suppressor protein p53 interacts specifically with several components of the general transcription machinery as well as numerous other cellular proteins. In the research presented here, nuclear magnetic resonance (NMR) and in vitro binding assays were used to examine the interaction between p53 and the cellular transcription factors TFIIH, CBP, and GATA. We have determined that p53 can bind to these three transcription factors through its amino-terminal acidic activation domain (AAD). Although all these factors bind to the same domain, it seems that they are each able to recognize distinct amino acids within the domain. Precise details like these are critical if we are to understand the intricacies of the transcription process.