Bacillus alvei ATCC 6348에서 Bav I methylase의 특성에 관한 연구

The purification and characterization of Bav Ⅰ methylase from B. alvei ATCC 6348 were investigated in the present reserch. The Bav Ⅰ methylase was partially purified by Sephadex G-150 and heparin-agarose column chromatography. The activity of the Bav Ⅰ methylase during the growth of B. alvei was maximal at the early exponential growth phase. The Bav Ⅰ methylase was maximally active at pH 7.5, 50~100 mM NaCl and was inhibited hypyridoxal 5’-phosphate above the concentration of 0.6mM. pBR 322 DNA cleaved by the Bav Ⅰ endonuclease was not methylated by the Bav Ⅰ methylase and pBR 322 DNA methylated by the Bav Ⅰ methylase was not cleaved by the Bav Ⅰ endonuclease. Therfore it is thought that lysine residue plays an important role in Bav Ⅰ methylase activity and the same DNA sequence is recognized by the Bav Ⅰ endonuclease and Bav Ⅰ methylase.