title: Canthaxanthin biosynthesis by the conversion of methylene to keto groups in a hydrocarbon beta-carotene by a single gene.
abstract: Compounds that include (a) keto group(s) in a molecule are ubiquitous natural components. A novel gene involved in ketocompound biosynthesis, designated crtW, was isolated from the marine bacteria Agrobacterium aurantiacum and Alcaligenes PC-1 that produce ketocarotenoids such as astaxanthin. When this gene was introduced into Escherichia coli that accumulated beta-carotene due to the Erwinia carotenogenic genes, the E. coli transformants synthesized canthaxanthin, one of ketocarotenoids, which was identified after purification by its visible, FD-MS and 1H-NMR spectral analysis. It has been demonstrated for the first time that one gene encodes an enzyme "ketolase" that catalyzes the conversion of methylene groups of a hydrocarbon beta-carotene to keto groups for synthesizing canthaxanthin via echinenone.
authors.affiliation: Central Laboratories for Key Technology, Kirin Brewery Co., Ltd., Kanagawa, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Misawa
authors.forename: S
authors.initials: S
authors.lastname: Kajiwara
authors.forename: K
authors.initials: K
authors.lastname: Kondo
authors.forename: A
authors.initials: A
authors.lastname: Yokoyama
authors.forename: Y
authors.initials: Y
authors.lastname: Satomi
authors.forename: T
authors.initials: T
authors.lastname: Saito
authors.forename: W
authors.initials: W
authors.lastname: Miki
authors.forename: T
authors.initials: T
authors.lastname: Ohtani
mesh_terms: D000421:Alcaligenes / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D016644:Canthaxanthin / Q000096:biosynthesis*; D002338:Carotenoids / Q000378:metabolism*; D002876:Chromosomes, Bacterial; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000302:isolation & purification / Q000378:metabolism; D004885:Erwinia / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D005798:Genes, Bacterial; D009682:Magnetic Resonance Spectroscopy; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010105:Oxygenases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D010957:Plasmids; D015183:Restriction Mapping; D012231:Rhizobium / Q000235:genetics / Q000378:metabolism*; D012623:Seawater; D017386:Sequence Homology, Amino Acid; D019207:beta Carotene
chemical_list: D001426:Bacterial Proteins; D004269:DNA, Bacterial; D019207:beta Carotene; D002338:Carotenoids; D016644:Canthaxanthin; D010105:Oxygenases; C093259:beta-carotene ketolase