IUBMB Enzyme Nomenclature


Accepted name: tRNA 4-demethylwyosine synthase (AdoMet-dependent)

Reaction: N1-methylguanine37 in tRNAPhe + pyruvate + S-adenosyl-L-methionine = 4-demethylwyosine37 in tRNAPhe + L-methionine + 5'-deoxyadenosine + CO2 + H2O

For diagram of reaction click here.

Glossary: 4-demethylwyosine = imG-14 = 6-methyl-3-(β-D-ribofuranosyl)-3,5-dihydro-9H-imidazo[1,2-a]purin-9-one

Other name(s): TYW1

Systematic name: tRNAPhe N1-methylguanine,pyruvate acetaldehyde-lyase (tRNAPhe 4-demethylwyosine-forming, decarboxylating, dehydrating)

Comments: This enzyme, which is a member of the superfamily of S-adenosyl-L-methionine-dependent radical (radical AdoMet) enzymes, binds two [4Fe-4S] clusters [3,4]. Carbons C2 and C3 from pyruvate are incorporated into 4-demethylwyosine [3]. The enzyme is found in eukaryotes where it is part of the pathway for wybutosine synthesis, and in archaea, where it is involved in the biosynthesis of archaeal wye bases, such as wyosine, isowyosine, and methylwyosine.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, PDB, CAS registry number:


1. Goto-Ito, S., Ishii, R., Ito, T., Shibata, R., Fusatomi, E., Sekine, S.I., Bessho, Y. and Yokoyama, S. Structure of an archaeal TYW1, the enzyme catalyzing the second step of wye-base biosynthesis. Acta Crystallogr. D Biol. Crystallogr. 63 (2007) 1059-1068. [PMID: 17881823]

2. Suzuki, Y., Noma, A., Suzuki, T., Senda, M., Senda, T., Ishitani, R. and Nureki, O. Crystal structure of the radical SAM enzyme catalyzing tricyclic modified base formation in tRNA. J. Mol. Biol. 372 (2007) 1204-1214. [PMID: 17727881]

3. Young, A.P. and Bandarian, V. Pyruvate is the source of the two carbons that are required for formation of the imidazoline ring of 4-demethylwyosine. Biochemistry 50 (2011) 10573-10575. [PMID: 22026549]

4. Perche-Letuvée, P., Kathirvelu, V., Berggren, G., Clemancey, M., Latour, J.M., Maurel, V., Douki, T., Armengaud, J., Mulliez, E., Fontecave, M., Garcia-Serres, R., Gambarelli, S. and Atta, M. 4-Demethylwyosine synthase from Pyrococcus abyssi is a radical-S-adenosyl-L-methionine enzyme with an additional [4Fe-4S]2+ cluster that interacts with the pyruvate co-substrate. J. Biol. Chem. 287 (2012) 41174-41185. [PMID: 23043105]

[EC created 2013]

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