title: Gibberellin biosynthesis in bacteria: separate ent-copalyl diphosphate and ent-kaurene synthases in Bradyrhizobium japonicum.
abstract: Gibberellins are ent-kaurene-derived diterpenoid phytohormones produced by plants, fungi, and bacteria. The distinct gibberellin biosynthetic pathways in plants and fungi are known, but not that in bacteria. Plants typically use two diterpene synthases to form ent-kaurene, while fungi use only a single bifunctional diterpene synthase. We demonstrate here that Bradyrhizobium japonicum encodes separate ent-copalyl diphosphate and ent-kaurene synthases. These are found in an operon whose enzymatic composition indicates that gibberellin biosynthesis in bacteria represents a third independently assembled pathway relative to plants and fungi. Nevertheless, sequence comparisons also suggest potential homology between diterpene synthases from bacteria, plants, and fungi.
authors.affiliation: Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
authors.forename: Dana
authors.initials: D
authors.lastname: Morrone
authors.forename: Jacob
authors.initials: J
authors.lastname: Chambers
authors.forename: Luke
authors.initials: L
authors.lastname: Lowry
authors.forename: Gunjune
authors.initials: G
authors.lastname: Kim
authors.forename: Aldwin
authors.initials: A
authors.lastname: Anterola
authors.forename: Kelly
authors.initials: K
authors.lastname: Bender
authors.forename: Reuben J
authors.initials: RJ
authors.lastname: Peters
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D020369:Bradyrhizobium / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D005875:Gibberellins / Q000096:biosynthesis*; D008969:Molecular Sequence Data; D009876:Operon; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D005875:Gibberellins; D010940:Plant Proteins; D019883:Alkyl and Aryl Transferases; C090963:ent-kaurene synthetase A; C105712:ent-kaurene synthetase B