Phytoene desaturase (lycopene forming)

Phytoene desaturase (lycopene-forming) (EC 1.3.99.31, 4-step phytoene desaturase, four-step phytoene desaturase, phytoene desaturase (ambiguous), CrtI (ambiguous)) is an enzyme with systematic name 15-cis-phytoene:acceptor oxidoreductase (lycopene-forming). This enzyme catalyses the following chemical reaction

15-cis-phytoene + 4 acceptor ⇌ all-trans-lycopene + 4 reduced acceptor (overall reaction)(1a) 15-cis-phytoene + acceptor ⇌ all-trans-phytofluene + reduced acceptor(1b) all-trans-phytofluene + acceptor ⇌ all-trans-zeta-carotene + reduced acceptor(1c) all-trans-zeta-carotene + acceptor ⇌ all-trans-neurosporene + reduced acceptor:(1d) all-trans-neurosporene + acceptor ⇌ all-trans-lycopene + reduced acceptor

This enzyme is involved in carotenoid biosynthesis.