Two‐Hybrid Dual Bait System

The yeast two-hybrid system, or interaction trap, is one of the most versatile methods available with which to identify and establish protein-protein interactions. The dual bait system is one adaptation of the classic approach. This system facilitates the simultaneous comparison of two distinct baits with one prey. One protein of interest is expressed as a fusion to the DNA-binding protein LexA (bait 1), while a second protein of interest is expressed as a fusion to the DNA-binding protein cI (bait 2). Strains of yeast engineered for screening of these dual baits possess four separate reporter genes. A plasmid expressing an activation domain-fused protein (prey), which can be either a defined protein interactor or a cDNA library, is also expressed to allow dual hybrid-mediated transcriptional activation.