A gamma subtype methylase, recognizes the double-stranded sequence 5'-CTCGAG-3', methylates A-5 on both strands, and protects the DNA from cleavage by the XhoI endonuclease. a 2'-deoxyadenosine in DNA + S-adenosyl-L-methionine = an N(6)-methyl-2'-deoxyadenosine in DNA + H(+) + S-adenosyl-L-homocysteine Belongs to the N(4)/N(6)-methyltransferase family.