Probable 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 condensation of N-methylguanine with 2 carbon atoms from pyruvate to form the tricyclic 4-demethylwyosine, an intermediate in wybutosine biosynthesis (By similarity). N(1)-methylguanosine(37) in tRNA(Phe) + pyruvate + S-adenosyl-L-methionine = 4-demethylwyosine(37) in tRNA(Phe) + 5'-deoxyadenosine + CO2 + H2O + L-methionine Binds 1 [4Fe-4S] cluster. The cluster is coordinated with 3 cysteines and an exchangeable S-adenosyl-L-methionine. tRNA modification; wybutosine-tRNA(Phe) biosynthesis. Belongs to the TYW1 family. Probable cloning artifact.