IUBMB Enzyme Nomenclature


Accepted name: 5-amino-6-(D-ribitylamino)uracil—L-tyrosine 4-hydroxyphenyl transferase

Reaction: 5-amino-6-(D-ribitylamino)uracil + L-tyrosine + S-adenosyl-L-methionine = 5-amino-5-(4-hydroxybenzyl)-6-(D-ribitylimino)-5,6-dihydrouracil + 2-iminoacetate + L-methionine + 5'-deoxyadenosine

For diagram of reaction click here.

Glossary: 5-amino-6-(D-ribitylamino)uracil = 5-amino-6-(1-D-ribitylamino)pyrimidine-2,4(1H,3H)-dione

Other name(s): cofH (gene name); cbiF (gene name) (ambiguous)

Systematic name: 5-amino-6-(D-ribitylamino)uracil:L-tyrosine, 4-hydroxyphenyl transferase

Comments: The enzyme is involved in the production of 7,8-didemethyl-8-hydroxy-5-deazariboflavin (Fo), the precursor of the redox cofactor coenzyme F420, which is found in methanogens and in various actinobacteria. Fo is also produced by some cyanobacteria and eukaryotes. The enzyme, which forms a complex with EC, 7,8-didemethyl-8-hydroxy-5-deazariboflavin synthase, is a radical SAM enzyme that uses the 5'-deoxyadenosyl radical to initiate the reaction.

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


1. Decamps, L., Philmus, B., Benjdia, A., White, R., Begley, T.P. and Berteau, O. Biosynthesis of F0, precursor of the F420 cofactor, requires a unique two radical-SAM domain enzyme and tyrosine as substrate. J. Am. Chem. Soc. 134 (2012) 18173-18176. [PMID: 23072415]

2. Philmus, B., Decamps, L., Berteau, O. and Begley, T.P. Biosynthetic versatility and coordinated action of 5'-deoxyadenosyl radicals in deazaflavin biosynthesis. J. Am. Chem. Soc. 137 (2015) 5406-5413. [PMID: 25781338]

[EC created 2010 as EC, part transferred 2018 to EC]

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