Type II restriction endonuclease BtgZI, obtainable from

In accordance with the present invention, there is provided a novel restriction endonuclease obtainable from Bacillus thermoglucosidasius 36A (NEB#1384), hereinafter referred to as “BtgZI”, which endonuclease: (1) recognizes the nucleotide sequence 5′-GCGATG-3′ in a double-stranded DNA molecule as shown below, 5′-GCGATGNNNNNNNNNN↓-3′ (SEQ ID NO:9) 3′-CGCTACNNNNNNNNNNNNNN↑-5′  (wherein G represents guanine, C represents cytosine, A represents adenine, T represents thymine and N represents either G, C, A, or T); (2) cleaves said sequence in the phosphodiester bonds between the 10th and the 11th nucleotides 3′ to the recognition sequence in the 5′-GCGATG-3 strand of the DNA, and between the 14th and 15th nucleotides 5′ to the recognition sequence in the complement stand, 5′-CATCGC-3′, to produce a 4 base 5′ extension; and (3) cleaves double-stranded pBR322 DNA to produce 3 fragments of 2892, 1181 and 288 base pairs.