An alpha subtype methylase that recognizes the double-stranded sequence 5'-GATC-3', methylates A-2 on both strands, and protects the DNA from cleavage by the MboI endonuclease (PubMed:12654995) (Probable). This seems to be a stronger methylase than M2.MboI (Probable). a 2'-deoxyadenosine in DNA + S-adenosyl-L-methionine = an N(6)-methyl-2'-deoxyadenosine in DNA + H(+) + S-adenosyl-L-homocysteine The MboI restriction system has two different methylases. Belongs to the N(4)/N(6)-methyltransferase family.