title: A non-synonymous nucleotide substitution can account for one evolutionary route to sesquiterpene synthase activity in the TPS-b subgroup.
abstract: Plant sesquiterpene and hemiterpene synthases in the monoterpene synthase dominated TPS-b subgroup are thought to have evolved independently from a monoterpene synthase ancestor. A TPS-b sesquiterpene synthase from apple (MdAFS1), which predominantly produces α-farnesene, can also synthesize the monoterpene (E)-β-ocimene. The dual activity offered a functional link to an ancestral MdAFS1 enzyme and a rational basis for investigation of the evolution of TPS-b sesquiterpene enzymes. Protein modelling and mutagenesis analysis of the MdAFS1 active site identified a non-synonymous nucleotide substitution that could account for the requisite shift in substrate specificity necessary for the emergence of its sesquiterpene activity during the evolution of the TPS-b enzymes.
authors.affiliation: The New Zealand Institute for Plant & Food Research Ltd, Plant & Food Research Mt Albert, Auckland, New Zealand. sol.green@plantandfood.co.nz
authors.forename: Sol
authors.initials: S
authors.lastname: Green
authors.forename: Edward N
authors.initials: EN
authors.lastname: Baker
authors.forename: William
authors.initials: W
authors.lastname: Laing
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics*; D019143:Evolution, Molecular; D017343:Genes, Plant; D010940:Plant Proteins / Q000235:genetics*; D017354:Point Mutation; D013379:Substrate Specificity / Q000235:genetics
chemical_list: D010940:Plant Proteins; D019883:Alkyl and Aryl Transferases; C108877:terpene synthase