tRNA hydroxylase that acts as a component of the wybutosine biosynthesis pathway. Wybutosine is a hyper modified guanosine with a tricyclic base found at the 3'-position adjacent to the anticodon of eukaryotic phenylalanine tRNA. Catalyzes the hydroxylation of 7-(a-amino-a-carboxypropyl)wyosine (yW-72) into undermodified hydroxywybutosine (OHyW*). OHyW* being further transformed into hydroxywybutosine (OHyW) by LCMT2/TYW4. OHyW is a derivative of wybutosine found in higher eukaryotes. 2-oxoglutarate + 7-[(3S)-3-amino-3-carboxypropyl]wyosine(37) in tRNA(Phe) + O2 = 7-(2-hydroxy-3-amino-3-carboxypropyl)wyosine(37) in tRNA(Phe) + CO2 + succinate Binds 1 Fe(2+) ion per subunit. tRNA modification; wybutosine-tRNA(Phe) biosynthesis. Homodimer. Belongs to the TYW5 family. Truncated N-terminus.