. "Catalysis of the reaction: S-adenosyl-L-methionine + guanine(37) in tRNA = N(1)-methylguanine(37) in tRNA + S-adenosyl-L-homocysteine." . . "tRNA (guanine(37)-N(1))-methyltransferase activity" . "transfer RNA (m(1)G(37)) methyltransferase activity" . "tRNA (m(1)G(37)) methyltransferase activity" . "tRNA-(N(1)G37) methyltransferase activity" . .