Dioxygenase that acts as on nucleic acids, such as DNA and tRNA. Requires molecular oxygen, alpha-ketoglutarate and iron. A number of activities have been described for this dioxygenase, but recent results suggest that it mainly acts as on tRNAs and mediates their demethylation or oxidation depending on the context and subcellular compartment. Mainly acts as a tRNA demethylase by removing N1-methyladenine from various tRNAs, with a preference for N1-methyladenine at position 58 (m1A58) present on a stem loop structure of tRNAs. Acts as a regulator of translation initiation and elongation in response to glucose deprivation: regulates both translation initiation, by mediating demethylation of tRNA(Met), and translation elongation, N1-methyladenine-containing tRNAs being preferentially recruited to polysomes to promote translation elongation. In mitochondrion, specifically interacts with mt-tRNA(Met) and mediates oxidation of mt-tRNA(Met) methylated at cytosine(34) to form 5-formylcytosine (f5c) at this position