Phytoene desaturase (zeta-carotene-forming)

Phytoene desaturase (zeta-carotene-forming) (, 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 $$\rightleftharpoons$$ all-trans-zeta-carotene + 2 reduced acceptor (overall reaction)
 * (1a) 15-cis-phytoene + acceptor $$\rightleftharpoons$$ all-trans-phytofluene + reduced acceptor
 * (1b) all-trans-phytofluene + acceptor $$\rightleftharpoons$$ all-trans-zeta-carotene + reduced acceptor

The enzyme is involved in carotenoid biosynthesis.