title: Structural investigation of heteroyohimbine alkaloid synthesis reveals active site elements that control stereoselectivity.
abstract: Plants produce an enormous array of biologically active metabolites, often with stereochemical variations on the same molecular scaffold. These changes in stereochemistry dramatically impact biological activity. Notably, the stereoisomers of the heteroyohimbine alkaloids show diverse pharmacological activities. We reported a medium chain dehydrogenase/reductase (MDR) from Catharanthus roseus that catalyses formation of a heteroyohimbine isomer. Here we report the discovery of additional heteroyohimbine synthases (HYSs), one of which produces a mixture of diastereomers. The crystal structures for three HYSs have been solved, providing insight into the mechanism of reactivity and stereoselectivity, with mutation of one loop transforming product specificity. Localization and gene silencing experiments provide a basis for understanding the function of these enzymes in vivo. This work sets the stage to explore how MDRs evolved to generate structural and biological diversity in specialized plant metabolism and opens the possibility for metabolic engineering of new compounds based on this scaffold.
authors.affiliation: The John Innes Centre, Department of Biological Chemistry, Norwich NR4 7UH, UK.
authors.forename: Anna
authors.initials: A
authors.lastname: Stavrinides
authors.affiliation: The John Innes Centre, Department of Biological Chemistry, Norwich NR4 7UH, UK.
authors.forename: Evangelos C
authors.initials: EC
authors.lastname: Tatsis
authors.affiliation: The John Innes Centre, Department of Biological Chemistry, Norwich NR4 7UH, UK.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Caputi
authors.affiliation: Université François-Rabelais de Tours, EA2106 'Biomolécules et Biotechnologies Végétales', Tours 37200, France.
authors.forename: Emilien
authors.initials: E
authors.lastname: Foureau
authors.affiliation: The John Innes Centre, Department of Biological Chemistry, Norwich NR4 7UH, UK.
authors.forename: Clare E M
authors.initials: CE
authors.lastname: Stevenson
authors.affiliation: The John Innes Centre, Department of Biological Chemistry, Norwich NR4 7UH, UK.
authors.forename: David M
authors.initials: DM
authors.lastname: Lawson
authors.affiliation: Université François-Rabelais de Tours, EA2106 'Biomolécules et Biotechnologies Végétales', Tours 37200, France.
authors.forename: Vincent
authors.identifier: 0000-0001-8902-4532
authors.initials: V
authors.lastname: Courdavault
authors.affiliation: The John Innes Centre, Department of Biological Chemistry, Norwich NR4 7UH, UK.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: O'Connor
mesh_terms: D020134:Catalytic Domain; D030008:Catharanthus / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D008958:Models, Molecular; D062105:Molecular Docking Simulation; D016297:Mutagenesis, Site-Directed; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011487:Protein Conformation; D046948:Secologanin Tryptamine Alkaloids / Q000737:chemistry* / Q000378:metabolism; D013237:Stereoisomerism; D014748:Vinca Alkaloids / Q000737:chemistry / Q000378:metabolism
chemical_list: D010940:Plant Proteins; D046948:Secologanin Tryptamine Alkaloids; D014748:Vinca Alkaloids; C021093:strictosidine