Probably a G subtype restriction enzyme that recognizes an undetermined sequence and cleaves at an undetermined site. Probably also acts as an alpha subtype methylase, presumably on the same sequence. Endonucleolytic cleavage of DNA to give specific double-stranded fragments with terminal 5'-phosphates. a 2'-deoxyadenosine in DNA + S-adenosyl-L-methionine = an N(6)-methyl-2'-deoxyadenosine in DNA + H(+) + S-adenosyl-L-homocysteine In the C-terminal section; belongs to the N(4)/N(6)-methyltransferase family.