INTEGRATION HOST FACTOR AMPLIFIES THE INDUCTION OF THE ACEBAK OPERON OF ESCHERICHIA-COLI BY RELIEVING ICLR REPRESSION

A binding site for integration host factor (IHF) was identified upstre am of the aceBAK promoter. Under inducing conditions, IHF activates ac eB::lacZ expression by opposing IclR repression. In contrast, IHF has little effect on aceB::lacZ expression under repressing conditions. Th e ability of IHF to relieve repression under inducing but not repressi ng conditions allows this protein to amplify the induction of aceBAK.