Systems for generating and detecting mutations in the galactose operon promoter region

We discuss the use of plasmid systems which enable us to generate and detect mutations in the Escherichia coli galactose operon promoter region. We describe the isolation of mutants which map the galactose promoters and which pinpoint the sites for the binding of the cyclic AMP-binding protein (CRP) and the galactose repressor. Finally, we describe how such mutations can be transferred from the plasmid systems to the intact galactose operon on the host chromosome.