ID 1.3.99.28 DE phytoene desaturase (neurosporene-forming). AN 3-step phytoene desaturase. CA 15-cis-phytoene + 3 A = 3 AH2 + all-trans-neurosporene. CC -!- This enzyme is involved in carotenoid biosynthesis and catalyzes up CC to three desaturation steps (cf. EC 1.3.99.29, EC 1.3.99.30, CC EC 1.3.99.31). CC -!- The enzyme is activated by FAD. CC -!- NAD(+), NADP(+) or ATP show no activating effect. DR P54980, CRTI_CERS4 ; P17054, CRTI_RHOCB ; //