IN-VIVO MUTATIONAL ANALYSIS OF BACTERIOPHAGE-MU OPERATORS

In bacteria lysogenic for bacteriophage Mu, the phage repressor binds to a tripartite operator region, O1,O2,O3, to repress the lytic promot er pE, located in O2, and negatively autoregulate its own synthesis at the pCM promoter located in O3. We isolated and characterized operato r mutations which lead to derepression of pE. Their location in the fi rst and third repressor-consensus-binding sequences in O2 confirms the importance of these sites for repressor/operator interactions.