Type II restriction endonucleases recognize short 4-8 bp nucleotide sequences and cleave phosphodiester bonds within or close to their target site. BsaWI restriction endonuclease from the thermophilic bacterium Bacillus stearothermophilus W1718 belon ...
Type II restriction endonucleases recognize short 4-8 bp nucleotide sequences and cleave phosphodiester bonds within or close to their target site. BsaWI restriction endonuclease from the thermophilic bacterium Bacillus stearothermophilus W1718 belongs to a group of restriction endonucleases that share CCGG motif within their target sites, termed 'CCGG-family'. However, the R-(D/E)R motif residues, which are supposed to recognize CCGG from the major groove side, are poorly ordered and located far away from the DNA bases. BsaWI contacts with the CCGG tetranucleotide from the minor groove side. It is folded into two domains an N-terminal helical domain and a C-terminal catalytic domain. Furthermore, it carries a PDXKXE motif at the putative active site [1].