THERMOPHILIC STRAIN BACILLUS SPECIES AA CONTAINS SEVERAL SITE-SPECIFIC ENDONUCLEASES

Thermophilic strain Bacillus species AA contains several site-specific endonucleases and three of them have been identified. BspAAI recogniz es the sequence 5'-C down arrow TCGAG-3' and cleaves it after the firs t ''C'' forming 4-nucleotide 5'-ends and is an isoschizomer of XhoI. B spAAII recognizes the sequence 5'T down arrow CTAGA-3' and cleaves it after the first ''T'' forming 4-nucleotide 5'-ends and is an isoschizo mer of XbaI. BspAAIII recognizes the sequence 5'-GGATCC-3' and is an i somer of BamHI. The optimal temperature and pH values are 42-48 degree s C and 7.0-8.0, respectively.