Processive cleavage of concatemer DNA duplexes by Eco RII restriction endonuclease.

Eco RII restriction endonuclease cleaves synthetic DNA-duplexes in which the recognition sites of this enzyme (5'...CCATGG...) are repeated every 9 base pairs with the alternating orientation of the central AT pair. It operates in a processive mode, i.e. the bound enzyme molecule slides along the substrate toward neighboring recognition sites. Nona-nucleotides are the main products of the cleavage. The data obtained neighboring recognition sites. Nona-nucleotides are the main products of the cleavage. The data obtained point to the capability of Eco RII endonuclease to recognize and cleave the substrate under both possible orientations of the central AT-pair of the recognition site with respect to the bound enzyme molecule. These data also show the close similarity of DNA structures in a complex with the enzyme and without.