Cloning of two carotenoid ketolase genes from Nostoc punctiforme for the heterologous production of canthaxanthin and astaxanthin.
For the heterologous synthesis of keto-carotenoids such as astaxanthin, two carotenoid ketolase genes crtW38 and crtW148, were cloned from the cyanobacterium, Nostoc punctiforme PCC 73102 and functionally characterized. Upon expression in Escherichia coli, both genes mediated the conversion of beta-carotene to canthaxanthin. However in a zeaxanthin-producing E. coli, only the gene product of crtW148 introduced 4-keto groups into the 3,3'-dihydroxy carotenoid zeaxanthin yielding astaxanthin. The gene product of crtW38 was unable to catalyze this reaction. Both ketolases differ in their interaction with a hydroxylase in the biosynthetic pathway from beta-carotene to astaxanthin.
Biosynthesis Group, Botanical Institute, Goethe University, P.O. Box 111932, D-60054 Frankfurt, Germany.
Sabine
S
Steiger
Gerhard
G
Sandmann
D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D016644:Canthaxanthin / Q000096:biosynthesis* / Q000235:genetics; D002338:Carotenoids / Q000378:metabolism*; D003001:Cloning, Molecular / Q000379:methods; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial / Q000502:physiology; D015971:Gene Expression Regulation, Enzymologic / Q000502:physiology; D008969:Molecular Sequence Data; D046937:Nostoc / Q000201:enzymology* / Q000378:metabolism*; D010105:Oxygenases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D024341:Xanthophylls; D019207:beta Carotene / Q000031:analogs & derivatives* / Q000096:biosynthesis* / Q000235:genetics
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D024341:Xanthophylls; D019207:beta Carotene; D002338:Carotenoids; D016644:Canthaxanthin; C005948:astaxanthine; D010105:Oxygenases; C093259:beta-carotene ketolase