title: Metabolic diversification--independent assembly of operon-like gene clusters in different plants.
abstract: Operons are clusters of unrelated genes with related functions that are a feature of prokaryotic genomes. Here, we report on an operon-like gene cluster in the plant Arabidopsis thaliana that is required for triterpene synthesis (the thalianol pathway). The clustered genes are coexpressed, as in bacterial operons. However, despite the resemblance to a bacterial operon, this gene cluster has been assembled from plant genes by gene duplication, neofunctionalization, and genome reorganization, rather than by horizontal gene transfer from bacteria. Furthermore, recent assembly of operon-like gene clusters for triterpene synthesis has occurred independently in divergent plant lineages (Arabidopsis and oat). Thus, selection pressure may act during the formation of certain plant metabolic pathways to drive gene clustering.
authors: Department of Metabolic Biology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK.
authors: Ben
authors: B
authors: Field
authors: Anne E
authors: AE
authors: Osbourn
mesh_terms: D000217:Acyltransferases / Q000235:genetics / Q000378:metabolism; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism* / Q000382:microbiology; D018554:Avena / Q000235:genetics; D003577:Cytochrome P-450 Enzyme System / Q000235:genetics / Q000378:metabolism; D019143:Evolution, Molecular; D015870:Gene Expression; D017343:Genes, Plant; D019751:Intramolecular Transferases / Q000235:genetics / Q000378:metabolism; D053858:Metabolic Networks and Pathways / Q000235:genetics; D005810:Multigene Family; D009876:Operon; D010935:Plant Diseases; D019441:Plant Epidermis / Q000378:metabolism; D018517:Plant Roots / Q000378:metabolism; D014315:Triterpenes / Q000378:metabolism*
chemical_list: D014315:Triterpenes; C528598:thalianol; D003577:Cytochrome P-450 Enzyme System; D000217:Acyltransferases; D019751:Intramolecular Transferases; C021924:lanosterol synthase