pseudouridine(54) in tRNA + S-adenosyl-L-methionine = N(1)-methylpseudouridine(54) in tRNA + S-adenosyl-L-homocysteine + H(+)
pseudouridine(54) in trna + s-adenosyl-l-methionine = n(1)-methylpseudouridine(54) in trna + s-adenosyl-l-homocysteine + h(+)