TYW5 uses 2-oxoglutarate and molecular oxygen to hydroxylate yW-72 (7-(3-amino-3-carboxypropyl)wyosine) at nucleotide 37 of tRNA(Phe), yielding OHyW-72 (7-(2-hydroxy-3-amino-3-carboxypropyl)wyosine), carbon dioxide, and succinate (Noma et al. 2010, Kato et al. 2011).