label: carboxy-S-adenosyl-L-methionine + 5-hydroxyuridine(34) in tRNA <=> 5-carboxymethoxyuridine(34) in tRNA + S-adenosyl-L-homocysteine + H(+)
label_lc: carboxy-s-adenosyl-l-methionine + 5-hydroxyuridine(34) in trna <=> 5-carboxymethoxyuridine(34) in trna + s-adenosyl-l-homocysteine + h(+)