Catalyzes the 2-oxoglutarate-dependent oxidation of tyrosine isonitrile. (2S)-3-(4-hydroxyphenyl)-2-isocyanopropanoate + 2-oxoglutarate + O2 = (2E)-3-(4-hydroxyphenyl)-2-isocyanoprop-2-enoate + CO2 + H2O + succinate Binds 1 Fe(2+) per subunit. kcat is 0.22 sec(-1). Belongs to the TfdA dioxygenase family.