Phytoene desaturase (zeta carotene forming)

Phytoene desaturase (zeta-carotene-forming) (EC 1.3.99.29, CrtIa, 2-step phytoene desaturase (ambiguous), two-step phytoene desaturase (ambiguous)) is an enzyme with systematic name 15-cis-phytoene:acceptor oxidoreductase (zeta-carotene-forming). This enzyme catalyses the following chemical reaction

15-cis-phytoene + 2 acceptor ⇌ all-trans-zeta-carotene + 2 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

The enzyme is involved in carotenoid biosynthesis.