label: an adenosine in tRNA + S-adenosyl-L-methionine <=> an N(1)-methyladenosine in tRNA + S-adenosyl-L-homocysteine + H(+)
label_lc: an adenosine in trna + s-adenosyl-l-methionine <=> an n(1)-methyladenosine in trna + s-adenosyl-l-homocysteine + h(+)