摘要 |
<p>The present invention relates to recombinant DNA which encodes the BpmI restriction endonuclease as well as BpmI methyltransferase, expression of BpmI restriction endonuclease from E. coli cells containing the recombinant DNA. BpmI endonuclease is a fusion of two distinct elements with a possible structural domains of restriction-methylationspecificity (R-M-S). This domain organization is analogous to the type I restriction-modification system with three distinct subunits, restriction, methylation, and specificity (R, M, and S). Because BpmI is quite distinct to other type IIS restriction enzymes, it is proposed that BpmI belongs to a subgroup of type II restriction enzymes called type IIf (f stands for fusion of restriction-modification-specificity domains). The Type IIf group of restriction enzyme includes Eco57I, BpmI, GsuI, BseRI and some other restriction enzymes that cut downstream sequences at long distance, 10-20 bp downstream of recognition sequence, such as MmeI (N20/N18)). <IMAGE></p> |