In vitro study of the interaction of the LexA repressor and the UvrC protein with a uvrC regulatory region.

The in vitro interaction of the LexA repressor with a regulatory region of the uvrC gene has been studied by polyacrylamide gel electrophoresis. Although the uvrC promoter region shows some homology with the canonic LexA binding site, no specific binding of the repressor to this DNA sequence could be observed, but only a cooperative nonspecific binding. By the same technique we show that the UvrC protein does not bind specifically to this regulatory DNA sequence either, although the protein is able to bind nonspecifically and cooperatively to the double-stranded DNA fragment.