Mapping of protein-protein interactions between c-myb and its coactivator CBP by a new phage display technique

We have developed a phage display technique for the mapping of protein-protein interaction sites and characterized the interaction between the c-myb proto-oncogene product and its co-activator CBP. Arbitrary DNA segments of the c-myb gene were cloned into a modified phagemid which allowed for expression in all possible reading frames. The mini-library encompassing all functional domains of the protein was propagated as phages and screened with different bait proteins. Alignment of the sequences revealed that the amino acids 317-342 of Myb interact with the CBP protein. Furthermore, an intramolecular interaction of the N-terminal Myb DNA binding domain with the C-terminus (amino acids 541-567) could be detected.