title: On heterogeneity of DNA methylases from Escherichia coli SK cells.
abstract: The presence of E. coli SK cells of five different DNA-methylases differing in specificity to the methylated sequence is documented has been proven. Two enzymes methylate cytosine with the formation of 5'-methylcytosine and three enzymes methylate adenine with formation of 6'-methylaminopurine. A method for simultaneous isolation of the five individual enzymes including gel filtration on Biogel A-0.5 M is proposed. The direct evidence has been presented showing that the additional methylation test in our method modification actually can discriminate between enzymes differing in sensitive sites.
mesh_terms: D000225:Adenine / Q000302:isolation & purification / Q000378:metabolism; D002850:Chromatography, Gel; D003596:Cytosine / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000302:isolation & purification* / Q000378:metabolism; D004926:Escherichia coli / Q000201:enzymology*; D008780:Methyltransferases / Q000302:isolation & purification*; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D013379:Substrate Specificity
chemical_list: D003596:Cytosine; D008780:Methyltransferases; D004248:DNA (Cytosine-5-)-Methyltransferases; D015265:Site-Specific DNA-Methyltransferase (Adenine-Specific); D000225:Adenine