Bci528I, a new isoschizomer of EcoRI isolated from Bacillus circulans 528

Bacillus circulans 528 produces a restriction endonuclease, Bci528I which is an isoschizomer of EcoRI. We purified the enzyme, using Sephadex G-150, Phospho-cellulose, DEAE-cellulose, Hepharin-Sepharose CL-6B chromatography. The specific activity of Bci528I was 29,400 U/mg·protein. Bci528I recognizes 5′-GAATTC-3′ in dsDNA and cleaves between G and A of the recognition sequence, producing a symmetric four base 5′overhang.