Interactions of the catabolite activator protein (CAP) at the galactose and lactose promoters of Escherichia coli probed by hydroxyl radical footprinting. The second CAP molecule which binds at gal and the one CAP at lac may act to stimulate transcription in the same way.

The catabolite activator protein (CAP) binding sites of the Escherichia coli galactose and lactose operons were probed by hydroxyl radical footprinting. This method reveals each base that is protected by the bound protein. The patterns of protection seen for the primary CAP sites at gal and lac were virtually identical.

Role of a second catabolite activator protein molecule in controlling initiation of transcription at the galactose operon of Escherichia coli.

The molecular mechanisms whereby RNA polymerase, catabolite activator protein (CAP), and cyclic AMP (cAMP) participate in transcriptional regulation at the galactose operon have been probed by a variety of in vitro techniques. Interactions between purified proteins and promoter-containing DNA fragments were assayed by gel electrophoresis, by resistance to restriction endonuclease digestion, and by monitoring runoff transcripts. The data bear on the multiple functions that CAP performs in gal control.

The binding of catabolite activator protein and RNA polymerase to the Escherichia coli galactose and lactose promoters probed by alkylation interference studies.

The Escherichia coli galactose and lactose promoter regions have been studied by alkylation interference experiments. The data reveal those bases or phosphate groups which, when modified, prevent the binding of the catabolite activator protein (CAP) or RNA polymerase and hence are presumably in contact with the proteins. Interference contacts made by CAP at its primary binding sites at gal and lac are quite similar, indicating that CAP-cAMP uses the same mode of binding at these two operons.

Kinetics of RNA polymerase-promoter complex formation: effects of nonspecific DNA-protein interactions.

The rates of formation of RNA polymerase-promoter open complexes at the galactose P2 and lactose UV5 promoters of E. coli were studied using polyacrylamide gels to separate the heparin-resistant complexes from unbound DNA. Both the apparent rate and extent of reaction at these promoters are inhibited at excess RNA polymerase.

Two catabolite activator protein molecules bind to the galactose promoter region of Escherichia coli in the presence of RNA polymerase.

The catabolite activator protein (CAP) of Escherichia coli, complexed with cAMP, is required for efficient initiation of transcription from the galactose P1 promoter (start site at +1) but not from the overlapping P2 promoter (start site at -5) [Musso, R. E., DiLauro, R.