title: CYP96T1 of Narcissus sp. aff. pseudonarcissus Catalyzes Formation of the Para-Para' C-C Phenol Couple in the Amaryllidaceae Alkaloids.
abstract: The Amaryllidaceae alkaloids are a family of amino acid derived alkaloids with many biological activities; examples include haemanthamine, haemanthidine, galanthamine, lycorine, and maritidine. Central to the biosynthesis of the majority of these alkaloids is a C-C phenol-coupling reaction that can have para-para', para-ortho', or ortho-para' regiospecificity. Through comparative transcriptomics of Narcissus sp. aff. pseudonarcissus, Galanthus sp., and Galanthus elwesii we have identified a para-para' C-C phenol coupling cytochrome P450, CYP96T1, capable of forming the products (10bR,4aS)-noroxomaritidine and (10bS,4aR)-noroxomaritidine from 4'-O-methylnorbelladine. CYP96T1 was also shown to catalyzed formation of the para-ortho' phenol coupled product, N-demethylnarwedine, as less than 1% of the total product. CYP96T1 co-expresses with the previously characterized norbelladine 4'-O-methyltransferase. The discovery of CYP96T1 is of special interest because it catalyzes the first major branch in Amaryllidaceae alkaloid biosynthesis. CYP96T1 is also the first phenol-coupling enzyme characterized from a monocot.
authors.affiliation: Donald Danforth Plant Science Center St. Louis, MO, USA.
authors.forename: Matthew B
authors.initials: MB
authors.lastname: Kilgore
authors.affiliation: Donald Danforth Plant Science Center St. Louis, MO, USA.
authors.forename: Megan M
authors.initials: MM
authors.lastname: Augustin
authors.affiliation: National Center for Genome Resources Santa Fe, NM, USA.
authors.forename: Gregory D
authors.initials: GD
authors.lastname: May
authors.affiliation: National Center for Genome Resources Santa Fe, NM, USA.
authors.forename: John A
authors.initials: JA
authors.lastname: Crow
authors.affiliation: Donald Danforth Plant Science Center St. Louis, MO, USA.
authors.forename: Toni M
authors.initials: TM
authors.lastname: Kutchan
keywords: Amaryllidaceae alkaloids; cytochrome P450; phenol coupling; secondary metabolism; transcriptomics