Isolation and characterization of CspBI, a novel NotI isoschizomer from Corynebacterium species B recognizing 5'-GC/GGCCGC-3'.

Sixty-seven bacterial strains were surveyed for the presence of type II restriction endonucleases, especially concerning super-rare-cutting enzymes. Fourteen strains were found to contain specific enzymes. One of them CspBI from Corynebacterium species B was purified and characterized as an isoschizomer of NotI, which recognizes the palindromic octanucleotide sequence 5'-GC/GGCCGC-3' and cleaves at the position shown by the arrow. A comparison between the cleavage patterns on different DNAs, obtained with partially purified endonucleases from other detected producents including some strains of Corynebacterium, Cellulomonas and Rhizobium has shown that these enzymes do not belong to super-rare-cutting restriction endonucleases.