IUBMB Enzyme Nomenclature


Accepted name: epoxyqueuosine reductase

Reaction: queuosine34 in tRNA + acceptor + H2O = epoxyqueuosine34 in tRNA + reduced acceptor

For diagram of reaction click here.

Glossary: queuine = base Q = 2-amino-5-({[(1S,4S,5R)-4,5-dihydroxycyclopent-2-en-1-yl]amino}methyl)-1,7-dihydropyrrolo[3,2-e]pyrimidin-4-one
epoxyqueine = base oQ

Other name(s): oQ reductase; QueG

Systematic name: queuosine34 in tRNA:acceptor oxidoreductase

Comments: This enzyme catalyses the last step in the bacterial biosynthetic pathway to queuosine, the modified guanosine base in the wobble position in tRNAs specific for Tyr, His, Asp or Asn.

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


1. Miles, Z.D., McCarty, R.M., Molnar, G. and Bandarian, V. Discovery of epoxyqueuosine (oQ) reductase reveals parallels between halorespiration and tRNA modification. Proc. Natl. Acad. Sci. USA 108 (2011) 7368-7372. [PMID: 21502530]

[EC created 2014]

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