Involved in the biosynthesis of the lanaridin cypemycin. The enzyme can methylate a variety of oligopeptides, cyclic peptides and the epsilon-amino group of lysine. N-terminal L-alanyl-[cypemycin] + 2 S-adenosyl-L-methionine = 3 H(+) + N-terminal N,N-dimethyl-L-alanyl-[cypemycin] + 2 S-adenosyl-L-homocysteine Belongs to the methyltransferase superfamily.