Agrococcus species 25 DNA was cloned in pUC19 plasmid of Escherichia coli. Cloned DNA fragment contained two Opened Reading Frames with 8 amino acid motives which belonged to amino DNAmethyltransferases. Thus M.AgsI can be the first of subunit adenine-(N6)-DNA methyltransferase. The enzyme was purified from the recombinant strain by chromatography on P-11 Phosphocellulose, Heparin-Sepharose and Hydroxyapatite. M.AgsI specificity was determined by a study of protection of lambda DNAmethylated withM.AgsI against cleavage with some restriction endonucleases.Asensitivity of restriction endonucleases to M.AgsI-methylation was studied.