Protein-Protein Interaction-Yeast two Hybrid System

Many proteins recognize and bind to other proteins. The total of all protein-protein interactions is sometimes referred to as the protein interactome by those enthusiastic about "omics" terminology. Mass screening of such interactions has proved possible by means of the "Two hybrid" system. It is assumed that the binding of a novel protein to one that is well characterized may provide some hint as the function. Two hybrid analyses depend on the modular structure of transcriptional activator proteins. Many of these proteins contain two factor domains -DNA Binding Domain (DBD) and Activation Domain (AD). The DBD recognizes a specific sequence in the DNA upstream of a promoter and the AD stimulates transcription by binding to RNA polymerase. Provided that the two domains interact, they will activate transcription. The whole experiment is based on this principle of Yeast two Hybrid