IUBMB Enzyme Nomenclature


Accepted name: lycopene elongase/hydratase (flavuxanthin-forming)

Reaction: (1) prenyl diphosphate + all-trans-lycopene + acceptor + H2O = nonaflavuxanthin + reduced electron acceptor + diphosphate
(2) prenyl diphosphate + nonaflavuxanthin + acceptor + H2O = flavuxanthin + reduced electron acceptor + diphosphate

For diagram of reaction click here

Glossary: flavuxanthin = 2,2'-bis-(4-hydroxy-3-methylbut-2-enyl)-1,16,1',16'-tetradehydro-1,2,1',2'-tetrahydro-ψ,ψ-carotene = (2E,8E,10E,12E,14E,16E,18E,20E,22E,24E,26E,28E,34E)-5,32-diisopropenyl-2,8,12,16,21,25,29,35-octamethylhexatriaconta-2,8,10,12,14,16,18,20,22,24,26,28,34-tridecaene-1,36-diol

Other name(s): crtEb (gene name)

Systematic name: prenyl-diphosphate:all-trans-lycopene prenyltransferase (hydrating, flavuxanthin-forming)

Comments: The enzyme, characterized from the bacterium Corynebacterium glutamicum, is bifunctional. It catalyses the elongation of the C40 carotenoid all-trans-lycopene by attaching an isoprene unit at C-2, as well as the hydroxylation of the new isoprene unit. The enzyme acts at both ends of the substrate, forming the C50 carotenoid flavuxanthin via the C45 intermediate nonaflavuxanthin. cf. EC, lycopene elongase/hydratase (dihydrobisanhydrobacterioruberin-forming).

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


1. Krubasik, P., Kobayashi, M. and Sandmann, G. Expression and functional analysis of a gene cluster involved in the synthesis of decaprenoxanthin reveals the mechanisms for C50 carotenoid formation. Eur. J. Biochem. 268 (2001) 3702-3708. [PMID: 11432736]

2. Heider, S.A., Peters-Wendisch, P. and Wendisch, V.F. Carotenoid biosynthesis and overproduction in Corynebacterium glutamicum. BMC Microbiol. 12 (2012) 198. [PMID: 22963379]

[EC created 2018]

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