Defining specificity of DNA methyltransferase M. Bsc4I in cellular lysate by blocking restriction endonucleases and computer modeling

The specificity of DNA methyltransferase M. Bsc4I was determined in cellular lysate of Bacillus schlegelii 4. The methylation sensitivity of restriction endonucleases and methylation modeling were used for this purpose. Modeling consisted of editing DNA sequences using replacements of methylated bases and their complementary bases. Substrate DNA treated with M. Bsc4I were used to study the sensitivity of some restrictases to methylation. It was shown that M. Bsc4I methylated 5′-Cm4CNNNNNNNGG-3′ and overlapping dcm-methylation blocked its activity. The suggested approach would be universal and simple for determining the specificity of DNA methyltransferases.