Pse31I

We have discovered a bacterial strain, Peribacillus species 31, which produces a novel restriction endonuclease named Pse31I. The enzyme recognizes a six-nucleotide non-palindromic DNA sequence, 5’-GGTCTC-3’, and cleaves it away from the recognition site at positions 1/5: 5’-GGTCTC(N)1^/3’-CCAGAG(N)5^-5’. Thus, Pse31I is a true isoschizomer of the restriction enzyme Eco31I . The producer strain was identified based on morphological and biochemical characteristics, as well as by analyzing the primary structure of a fragment of the 16S rRNA gene. Pse31I exhibits maximal activity at 37°C and is inactivated by incubation at 55°C and 65°C. The enzyme does not cleave sites containing a methylated cytosine in the top strand (5’-GGTCT(5mC)-3’) and/or in the bottom strand (3’-(5mC)CAGAG). The optimal reaction conditions for the enzyme include SE-buffer 5 (Y) (33 mM Tris-acetate (pH 7.9), 10 mM Mg-acetate, 66 mM K-acetate, 1 mM DTT) and a temperature of 37°C