IUBMB Enzyme Nomenclature


Accepted name: torulene dioxygenase

Reaction: torulene + O2 = 4'-apo-β,ψ-caroten-4'-al + 3-methylbut-2-enal

For diagram of reaction click here

Glossary: torulene = 3',4'-didehydro-β,ψ-carotene

Other name(s): CAO-2; CarT

Systematic name: torulene:oxygen oxidoreductase

Comments: It is assumed that 3-methylbut-2-enal is formed. The enzyme cannot cleave the saturated 3',4'-bond of γ-carotene which implies that a 3',4'-double bond is neccessary for this reaction.

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


1. Prado-Cabrero, A., Estrada, A.F., Al-Babili, S. and Avalos, J. Identification and biochemical characterization of a novel carotenoid oxygenase: elucidation of the cleavage step in the Fusarium carotenoid pathway. Mol. Microbiol. 64 (2007) 448-460. [PMID: 17493127]

2. Saelices, L., Youssar, L., Holdermann, I., Al-Babili, S. and Avalos, J. Identification of the gene responsible for torulene cleavage in the Neurospora carotenoid pathway. Mol. Genet. Genomics 278 (2007) 527-537. [PMID: 17610084]

3. Estrada, A.F., Maier, D., Scherzinger, D., Avalos, J. and Al-Babili, S. Novel apocarotenoid intermediates in Neurospora crassa mutants imply a new biosynthetic reaction sequence leading to neurosporaxanthin formation. Fungal Genet. Biol. 45 (2008) 1497-1505. [PMID: 18812228]

[EC created 2011]

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