The yeast two-hybrid system was first established by Fields and Song in their study of eukaryotic gene transcription regulation. Typical eukaryotic transcription factors, such as GAL4, GCN4, etc., contain two different structural domains: a DNA-binding domain and a transcription-activating domain.

The yeast two-hybrid system is a genetic system for analyzing protein-protein interactions in yeast and a genetic method based on the modular structure of transcription factors. Since its establishment, the method has been continuously improved and developed to not only detect interactions between known proteins, but more importantly, to discover new unknown proteins that interact with known proteins.