[Cytokinins do not noticeably change the methylation of adenine residues of DNA in cultured Escherichia coli B].

6-Benzylaminopurine (6-BAP) (1 mg/ml) does not influence the growth of E. coli B cell cultures or the number of [8-14C] labeled N6-methyladenine (m6A) residues in the total DNA [(100.m6A/(A x m6A) = 1.7]. The growth of bacterial cells in the presence of adenine or cytokinins (6-BAP, kinetin, zeatin) (1 mg/ml) was unaccompanied by significant changes in the intracellular content of plasmid pBR 322. The mode of restriction by endonuclease Cfu I hydrolyzing the Gm6ATC site of plasmids pBR 322 from E. coli B cells grown in the presence of adenine or one of the above-mentioned cytokinins is identical. These plasmids also have identical restriction products Mbo I or Sau 3AI. Thus, the cytokinins under study do not markedly affect the methylation of adenine residues in total DNA of E. coli B cell cultures and the GATC sequence in plasmids pBR 322 isolated from these cells.