FUNCTIONAL DOMAINS IN FLAVOBACTERIUM OKEANOKOITES (FOKI) RESTRICTION ENDONUCLEASE

摘要

The present inventors have identified the recognition and cleavage domains of the FokI restriction endonuclease. Accordingly, the present invention relates to DNA segments encoding the recognition and cleavage domains of the FokI restriction endonuclease, respectively. The 41 kDa N-terminal fragment constitutes the FokI recognition domain while the 25 kDa C-terminal fragment constitutes the FokI cleavage nuclease domain. The present invention also relates to hybrid restriction enzymes comprising the nuclease domain of the FokI restriction endonuclease linked to a recognition domain of another enzyme. One such hybrid restriction enzyme is Ubx-FN &cir& _. This enzyme contains the homeo domain of Ubx linked to the cleavage or nuclease domain of FokI. Additionally, the present invention relates to the construction of two insertion mutants of FokI endonuclease.