Involved in the biosynthesis of rhabduscin, a tyrosine derivative which is a potent inhibitor of phenoloxidase, a key component of the insect's innate immune system (PubMed:22711807). Catalyzes the 2-oxoglutarate-dependent oxidative decarboxylation of tyrosine isonitrile (PubMed:25866990). (2S)-3-(4-hydroxyphenyl)-2-isocyanopropanoate + 2-oxoglutarate + H(+) + O2 = 4-[(E)-2-isocyanoethenyl]phenol + 2 CO2 + H2O + succinate Binds 1 Fe(2+) per subunit. kcat is 5.1 sec(-1). Deletion of pvcA and pvcB abolishes rhabduscin biosynthesis and decreases virulence of the strain. Belongs to the TfdA dioxygenase family.