Bacillus macerans의 BmaI methylase의 특성

Characteriaation of BmaI methylase from bacillus macerans

The isolation and characterization of a new type II methylase, BmaI methylase, from Bacillus macerans ATCC 8244 were described. BmaI methylase was isolated by procedures of ammonium sulfate fractionation, DEAE-cellulose chromatography and phosphocellulose chromatography. Two types of methylases were present in this strain and only one of the two was a site specific BmaI methylase. The pBR322 DNA methylated by BmaI methylase was not cleaved by BmaI endonuclease, and pBR322 DNA cleaved by BmaI endonuclease was not methylated by BmaI methylase. The optimal pH for the BmaI methylase activity was 7.5, and optimal NaCl concentration was about 50 mM. BmaI methylase could methylate single-stranded M13mp18 DNA.