title: 7-deoxyloganetic acid synthase catalyzes a key 3 step oxidation to form 7-deoxyloganetic acid in Catharanthus roseus iridoid biosynthesis.
abstract: Iridoids are key intermediates required for the biosynthesis of monoterpenoid indole alkaloids (MIAs), as well as quinoline alkaloids. Although most iridoid biosynthetic genes have been identified, one remaining three step oxidation required to form the carboxyl group of 7-deoxyloganetic acid has yet to be characterized. Here, it is reported that virus-induced gene silencing of 7-deoxyloganetic acid synthase (7DLS, CYP76A26) in Catharanthus roseus greatly decreased levels of secologanin and the major MIAs, catharanthine and vindoline in silenced leaves. Functional expression of this gene in Saccharomyces cerevisiae confirmed its function as an authentic 7DLS that catalyzes the 3 step oxidation of iridodial-nepetalactol to form 7-deoxyloganetic acid. The identification of CYP76A26 removes a key bottleneck for expression of iridoid and related MIA pathways in various biological backgrounds.
authors.affiliation: Department of Biological Sciences, 500 Glenridge Avenue, Brock University, St. Catharines, Ontario L2S 3A1, Canada. Electronic address: vs08to@badger.ac.brocku.ca.
authors.forename: Vonny
authors.initials: V
authors.lastname: Salim
authors.affiliation: Department of Biological Sciences, 500 Glenridge Avenue, Brock University, St. Catharines, Ontario L2S 3A1, Canada. Electronic address: bw09ep@badger.ac.brocku.ca.
authors.forename: Brent
authors.initials: B
authors.lastname: Wiens
authors.affiliation: Department of Biological Sciences, 500 Glenridge Avenue, Brock University, St. Catharines, Ontario L2S 3A1, Canada. Electronic address: smasadaatsumi@nihs.go.jp.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Masada-Atsumi
authors.affiliation: Department of Biological Sciences, 500 Glenridge Avenue, Brock University, St. Catharines, Ontario L2S 3A1, Canada. Electronic address: fyu0506@gmail.com.
authors.forename: Fang
authors.initials: F
authors.lastname: Yu
authors.affiliation: Department of Biological Sciences, 500 Glenridge Avenue, Brock University, St. Catharines, Ontario L2S 3A1, Canada. Electronic address: vdeluca@brocku.ca.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: De Luca
mesh_terms: D000595:Amino Acid Sequence; D055162:Biocatalysis; D053898:Biosynthetic Pathways / Q000235:genetics; D030008:Catharanthus / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism*; D020868:Gene Silencing; D057888:Iridoid Glucosides / Q000378:metabolism*; D039823:Iridoids / Q000378:metabolism*; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014748:Vinca Alkaloids / Q000096:biosynthesis*
chemical_list: D057888:Iridoid Glucosides; D039823:Iridoids; D010940:Plant Proteins; D014748:Vinca Alkaloids; C021086:secologanin; D003577:Cytochrome P-450 Enzyme System
keywords: 7-Deoxyloganetic acid synthase; Apocynaceae; Catharanthus roseus; Functional characterization; Madagascar Periwinkle; Secologanin biosynthesis; Virus induced gene silencing