The separate DNA binding and activating domains of gal4 were revealed in two complementary experiments 1. Expression of the N-terminal region (DNA-binding domain)of the activator produces a protein bound to the dna normally but did not activate transcription 2. Fusion of the c-terminal region (activation domain) of the activator to the dna binding domain of a bacterial repressor LexA activates the transcription of the reporter gene Domain swap experimentThe separate DNA binding and activating domains of Gal4 were revealed in two complementary experiments 1. Expression of the N-terminal region (DNA-binding domain) of the activator produces a protein bound to the DNA normally but did not activate transcription. 2. Fusion of the C-terminal region (activation domain) of the activator to the DNA binding domain of a bacterial repressor, LexA activates the transcription of the reporter gene. Domain swap experiment