EC Explorer

1.3.99.27

1-hydroxycarotenoid 3,4-desaturase

1-hydroxy-1,2-dihydrolycopene + acceptor = 1-hydroxy-3,4-didehydro-1,2-dihydrolycopene + reduced acceptor

CrtD, hydroxyneurosporene desaturase, carotenoid 3,4-dehydrogenase, 1-hydroxy-carotenoid 3,4-dehydrogenase

1-hydroxy-1,2-dihydrolycopene:acceptor oxidoreductase

The enzymes from Rubrivivax gelatinosus and Rhodobacter sphaeroides prefer the acyclic carotenoids (e.g. 1-hydroxy-1,2-dihydroneurosporene, 1-hydroxy-1,2-dihydrolycopene) as substrates. The conversion rate for the 3,4-desaturation of the monocyclic 1′-hydroxy-1′,2′-dihydro-γ-carotene is lower [2,3]. The enzyme from the marine bacterium strain P99-3 shows high activity with the monocyclic carotenoid 1′-hydroxy-1′,2′-dihydro-γ-carotene [1]. The enzyme from Rhodobacter sphaeroides utilizes molecular oxygen as the electron acceptor in vitro [3]. However, oxygen is unlikely to be the natural electron acceptor under anaerobic conditions.

created 2011