title: In vitro expression and activity of lycopene cyclase and beta-carotene hydroxylase from Erwinia herbicola.
abstract: The cyclisation of lycopene to beta-carotene and the hydroxylation of beta-carotene to zeaxanthin are common enzymatic steps in the biosynthesis of carotenoids in a wide range of bacteria, fungi, and plants. We have individually expressed in E. coli the two genes coding for these enzymatic steps in Erwinia herbicola. The cyclase and hydroxylase enzymes have apparent molecular weights of 43 kDa and 22 kDa, respectively, as determined by SDS-PAGE. Hydroxylase in vitro activity was obtained only in the cytoplasmic fraction. Cyclase also demonstrated enzyme activity in a crude cell-free lysate, although to a lesser extent.
authors.affiliation: Department of Chemistry, University of California, Lawrence Berkeley Laboratory, Berkeley 94720.
authors.forename: B S
authors.initials: BS
authors.lastname: Hundle
authors.forename: D A
authors.initials: DA
authors.lastname: O'Brien
authors.forename: P
authors.initials: P
authors.lastname: Beyer
authors.forename: H
authors.initials: H
authors.lastname: Kleinig
authors.forename: J E
authors.initials: JE
authors.lastname: Hearst
mesh_terms: D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D004269:DNA, Bacterial; D004587:Electrophoresis, Agar Gel; D004591:Electrophoresis, Polyacrylamide Gel; D004885:Erwinia / Q000201:enzymology*; D004926:Escherichia coli; D019753:Intramolecular Lyases; D007535:Isomerases / Q000235:genetics / Q000378:metabolism*; D006899:Mixed Function Oxygenases / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D010957:Plasmids
chemical_list: D004269:DNA, Bacterial; D006899:Mixed Function Oxygenases; C079232:beta-carotene hydroxylase; D007535:Isomerases; D019753:Intramolecular Lyases; C070925:lycopene cyclase-isomerase