IUBMB Enzyme Nomenclature


Accepted name: phytoene desaturase (3,4-didehydrolycopene-forming)

Reaction: 15-cis-phytoene + 5 acceptor = all-trans-3,4-didehydrolycopene + 5 reduced acceptor (overall reaction)
(1a) 15-cis-phytoene + acceptor = all-trans-phytofluene + reduced acceptor
(1b) all-trans-phytofluene + acceptor = all-trans-ζ-carotene + reduced acceptor
(1c) all-trans-ζ-carotene + acceptor = all-trans-neurosporene + reduced acceptor
(1d) all-trans-neurosporene + acceptor = all-trans-lycopene + reduced acceptor
(1e) all-trans-lycopene + acceptor = all-trans-3,4-didehydrolycopene + reduced acceptor

For diagram of reaction click here.

Other name(s): 5-step phytoene desaturase; five-step phytoene desaturase; phytoene desaturase (ambiguous); Al-1

Systematic name: 15-cis-phytoene:acceptor oxidoreductase (3,4-didehydrolycopene-forming)

Comments: This enzyme is involved in carotenoid biosynthesis and catalyses up to five desaturation steps (cf. EC [phytoene desaturase (neurosporene-forming)], EC [phytoene desaturase (ζ-carotene-forming)] and EC [phytoene desaturase (lycopene-forming)]).

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


1. Hausmann, A. and Sandmann, G. A single five-step desaturase is involved in the carotenoid biosynthesis pathway to β-carotene and torulene in Neurospora crassa. Fungal Genet. Biol. 30 (2000) 147-153. [PMID: 11017770]

2. 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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