Is DNA unwound by the cyclic AMP receptor protein?

Abstract
Superhelical pBR 322 derivatives have been relaxed by eukaryotic topoisomerase I in the presence or in the absence of E. coli cyclic AMP receptor protein (CRP) and of cyclic AMP (cAMP). CRP alone, or cAMP alone do not affect the average linking number of the distribution of the relaxed to poisomers. Hence, they do not unwind the template.