title: Metabolism of cyclic carotenoids: a model for the alteration of this biosynthetic pathway in Capsicum annuum chromoplasts.
abstract: The biosynthetic pathway of cyclic carotenoid is known to be quantitatively and qualitatively different in the non-green plastids of Capsicum annuum fruits compared with chloroplasts. Here, the cloning is described of a novel cDNA from this organism, which encodes an enzyme catalyzing the cyclization of lycopene to beta-carotene when expressed in Escherichia coli. The corresponding gene is constitutively expressed during fruit development. Significant amino acid sequence identity was observed between this enzyme and capsanthin/capsorubin synthase which is involved in the synthesis of the species-specific red carotenoids of C. annuum fruits. The latter enzyme was found also to possess a lycopene beta-cyclase activity when expressed in E. coli. A model is proposed for the origin of the capsanthin/capsorubin synthase gene and the role of this enzyme, together with the newly cloned lycopene cyclase, in the specific re-channeling of linear carotenoids into beta-cyclic carotenoids in C. annuum ripening fruits.
authors.affiliation: Institut de Biologie Moléculaire des Plantes du CNRS, Strasbourg, France.
authors.forename: P
authors.initials: P
authors.lastname: Hugueney
authors.forename: A
authors.initials: A
authors.lastname: Badillo
authors.forename: H C
authors.initials: HC
authors.lastname: Chen
authors.forename: A
authors.initials: A
authors.lastname: Klein
authors.forename: J
authors.initials: J
authors.lastname: Hirschberg
authors.forename: B
authors.initials: B
authors.lastname: Camara
authors.forename: M
authors.initials: M
authors.lastname: Kuntz
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D002212:Capsicum / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D002338:Carotenoids / Q000378:metabolism*; D002736:Chloroplasts / Q000378:metabolism*; D003001:Cloning, Molecular; D016384:Consensus Sequence; D018076:DNA, Complementary; D004926:Escherichia coli; D019753:Intramolecular Lyases; D007535:Isomerases / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D000077276:Lycopene; D008969:Molecular Sequence Data; D010946:Plants, Medicinal; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019207:beta Carotene
chemical_list: D018076:DNA, Complementary; D011994:Recombinant Proteins; D019207:beta Carotene; D002338:Carotenoids; D007535:Isomerases; D019753:Intramolecular Lyases; C070925:lycopene cyclase-isomerase; D000077276:Lycopene