putrescine + S-adenosyl-L-methionine => N-methylputrescine + S-adenosyl-L-homocysteine + H(+)
putrescine + s-adenosyl-l-methionine => n-methylputrescine + s-adenosyl-l-homocysteine + h(+)
putrescine + S-adenosyl-L-methionine => N-methylputrescine + S-adenosyl-L-homocysteine + H(+)
putrescine + s-adenosyl-l-methionine => n-methylputrescine + s-adenosyl-l-homocysteine + h(+)