| Synonyms |
alr3189, beta-C-4 oxygenase;, beta-C-4-oxygenase, beta-carotene 3-hydroxylase/4-ketolase, beta-carotene 4,4′-oxygenase, beta-carotene ketolase, bkt, bkt1, BKT3, CrtO, CrtO beta-carotene ketolase, CrtO ketolase, crtS, CrtW, CrtW ketolase, CrtW148, CrtW38, DR0093, OBKT, slr0088 |
| Comments |
The enzyme, studied from algae, plants, fungi, and bacteria, adds an oxo group at position 4 of a carotenoid ¦Â ring. It is involved in the biosynthesis of carotenoids such as astaxanthin and flexixanthin. The enzymes does not act on ¦Â rings that are hydroxylated at position 3, such as in zeaxanthin (cf. EC 1.14.99.64, zeaxanthin 4-ketolase). The enzyme from the yeast Xanthophyllomyces dendrorhous is bifuntional and also catalyses the activity of EC 1.14.15.24, ¦Â-carotene 3-hydroxylase. |
