REVERSE 2-HYBRID AND ONE-HYBRID SYSTEMS TO DETECT DISSOCIATION OF PROTEIN-PROTEIN AND DNA-PROTEIN INTERACTIONS

Macromolecular interactions define many biological phenomena. Although genetic methods are available to identify novel protein-protein acid DNA-protein interactions, no genetic system has thus far been describe d to identify molecules or mutations that dissociate known interaction s. Herein, we describe genetic systems that detect such events in the yeast Saccharomyces cerevisiae, We have engineered yeast strains in wh ich the interaction of two proteins expressed in the context of the tw o-hybrid system or the interaction between a DNA-binding protein and i ts binding site in the context of the one-hybrid system is deleterious to growth, Under these conditions, dissociation of the interaction pr ovides a selective growth advantage, thereby facilitating detection, T hese methods referred to as the ''reverse two-hybrid system'' and ''re verse one-hybrid system'' facilitate the study of the structure-functi on relationships and regulation of protein-protein and DNA-protein int eractions, They should also facilitate the selection of dissociator mo lecules that could be used as therapeutic agents.