title: Insights into the formation of carlactone from in-depth analysis of the CCD8-catalyzed reactions.
abstract: Strigolactones are a new class of phytohormones synthesized from carotenoids via carlactone. The complex structure of carlactone is not easily deducible from its precursor, a cis-configured β-carotene cleavage product, and is thus formed via a poorly understood series of reactions and molecular rearrangements, all catalyzed by only one enzyme, the carotenoid cleavage dioxygenase 8 (CCD8). Moreover, the reactions leading to carlactone are expected to form a second, yet unidentified product. In this study, we used13C and18O-labeling to shed light on the reactions catalyzed by CCD8. The characterization of the resulting carlactone by LC-MS and NMR, and the identification of the assumed, less accessible second product allowed us to formulate a minimal reaction mechanism for carlactone generation.
authors.affiliation: Faculty of Biology, University of Freiburg, Germany.
authors.forename: Mark
authors.initials: M
authors.lastname: Bruno
authors.affiliation: Department of Chemistry and Biochemistry, University of Bern, Switzerland.
authors.forename: Martina
authors.initials: M
authors.lastname: Vermathen
authors.affiliation: Faculty of Biology, University of Freiburg, Germany.
authors.forename: Adrian
authors.initials: A
authors.lastname: Alder
authors.affiliation: Faculty of Biology, University of Freiburg, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Wüst
authors.affiliation: Faculty of Biology, University of Freiburg, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Schaub
authors.affiliation: Buchem b.v. Biopartner 3, Leiden, the Netherlands.
authors.forename: Rob
authors.initials: R
authors.lastname: van der Steen
authors.affiliation: Faculty of Biology, University of Freiburg, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Beyer
authors.affiliation: Department of Biology, University of Konstanz, Germany.
authors.forename: Sandro
authors.initials: S
authors.lastname: Ghisla
authors.affiliation: Faculty of Biology, University of Freiburg, Germany.|BESE Division, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia.
authors.forename: Salim
authors.initials: S
authors.lastname: Al-Babili
mesh_terms: D055162:Biocatalysis; D002247:Carbon Isotopes; D002338:Carotenoids / Q000737:chemistry*; D049308:Dioxygenases / Q000737:chemistry* / Q000302:isolation & purification; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D015870:Gene Expression; D007783:Lactones / Q000138:chemical synthesis*; D010103:Oxygen Isotopes; D018532:Pisum sativum / Q000737:chemistry / Q000201:enzymology; D010937:Plant Growth Regulators / Q000138:chemical synthesis*; D010940:Plant Proteins / Q000737:chemistry* / Q000302:isolation & purification; D011994:Recombinant Proteins / Q000737:chemistry / Q000302:isolation & purification; D019207:beta Carotene / Q000737:chemistry*
chemical_list: D002247:Carbon Isotopes; D007783:Lactones; D010103:Oxygen Isotopes; D010937:Plant Growth Regulators; D010940:Plant Proteins; D011994:Recombinant Proteins; C427759:beta-apo-10'-carotenal; C571055:carlactone; D019207:beta Carotene; D002338:Carotenoids; D049308:Dioxygenases
keywords: apocarotenoid; carlactone; carotenoid; carotenoid cleavage dioxygenase; strigolactone