title: Modularity of plant metabolic gene clusters: a trio of linked genes that are collectively required for acylation of triterpenes in oat.
abstract: Operon-like gene clusters are an emerging phenomenon in the field of plant natural products. The genes encoding some of the best-characterized plant secondary metabolite biosynthetic pathways are scattered across plant genomes. However, an increasing number of gene clusters encoding the synthesis of diverse natural products have recently been reported in plant genomes. These clusters have arisen through the neo-functionalization and relocation of existing genes within the genome, and not by horizontal gene transfer from microbes. The reasons for clustering are not yet clear, although this form of gene organization is likely to facilitate co-inheritance and co-regulation. Oats (Avena spp) synthesize antimicrobial triterpenoids (avenacins) that provide protection against disease. The synthesis of these compounds is encoded by a gene cluster. Here we show that a module of three adjacent genes within the wider biosynthetic gene cluster is required for avenacin acylation. Through the characterization of these genes and their encoded proteins we present a model of the subcellular organization of triterpenoid biosynthesis.
authors.affiliation: John Ines Centre, Norwich NR4 7UH, United Kingdom.
authors.forename: Sam T
authors.initials: ST
authors.lastname: Mugford
authors.forename: Thomas
authors.initials: T
authors.lastname: Louveau
authors.forename: Rachel
authors.initials: R
authors.lastname: Melton
authors.forename: Xiaoquan
authors.initials: X
authors.lastname: Qi
authors.forename: Saleha
authors.initials: S
authors.lastname: Bakht
authors.forename: Lionel
authors.initials: L
authors.lastname: Hill
authors.forename: Tetsu
authors.initials: T
authors.lastname: Tsurushima
authors.forename: Suvi
authors.initials: S
authors.lastname: Honkanen
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Rosser
authors.forename: George P
authors.initials: GP
authors.lastname: Lomonossoff
authors.forename: Anne
authors.initials: A
authors.lastname: Osbourn
mesh_terms: D000215:Acylation; D000217:Acyltransferases / Q000145:classification / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000378:metabolism / Q000494:pharmacology; D001203:Ascomycota / Q000472:pathogenicity; D018554:Avena / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008745:Methylation; D008780:Methyltransferases / Q000145:classification / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D005810:Multigene Family; D009154:Mutation; D010802:Phylogeny; D010935:Plant Diseases / Q000382:microbiology; D010940:Plant Proteins / Q000145:classification / Q000235:genetics / Q000378:metabolism; D018517:Plant Roots / Q000235:genetics / Q000378:metabolism; D012503:Saponins / Q000235:genetics / Q000378:metabolism*; D013329:Structure-Activity Relationship; D014026:Nicotiana / Q000235:genetics / Q000378:metabolism; D014315:Triterpenes / Q000378:metabolism*
chemical_list: D000935:Antifungal Agents; D010940:Plant Proteins; D012503:Saponins; D014315:Triterpenes; C091460:avenacin A 1; D008780:Methyltransferases; D000217:Acyltransferases