title: Purification and characterization of UDP-arabinopyranose mutase from Chlamydomonas reinhardtii.
abstract: Chlamydomonas reinhardtii cells are surrounded by a mixture of hydroxyprolin-rich glycoproteins consisting of L-arabinose, D-galactose, D-glucose, and D-mannose residues. The L-arabinose residue is thought to be attached by a transfer of UDP-L-arabinofuranose (UDP-Araf), which is produced from UDP-L-arabinopyranose (UDP-Arap) by UDP-arabinopyranose mutase (UAM). UAM was purified from the cytosol to determine the involvement of C. reinhardtii UAM (CrUAM) in glycoprotein synthesis. CrUAM was purified 94-fold to electrophoretic homogeneity by hydrophobic and size-exclusion chromatography. CrUAM catalyzed the reversible conversion between UDP-Arap and UDP-Araf and exhibited autoglycosylation activity when UDP-D-[(14)C]glucose was added as substrate. Compared to the properties of native and recombinant CrUAM overexpressed in Escherichia coli, native CrUAM showed a higher affinity for UDP-Arap than recombinant CrUAM did. This increased affinity for UDP-Arap might have been caused by post-translational modifications that occur in eukaryotes but not in prokaryotes.
authors.affiliation: Faculty of Agriculture, University of the Ryukyus.
authors.forename: Ayana
authors.initials: A
authors.lastname: Kotani
authors.forename: Maki
authors.initials: M
authors.lastname: Tsuji
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Azama
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ishii
authors.forename: Takumi
authors.initials: T
authors.lastname: Takeda
authors.forename: Tetsuro
authors.initials: T
authors.lastname: Yamashita
authors.forename: Mie
authors.initials: M
authors.lastname: Shimojima
authors.forename: Teruko
authors.initials: T
authors.lastname: Konishi
mesh_terms: D016825:Chlamydomonas reinhardtii / Q000166:cytology / Q000201:enzymology*; D019751:Intramolecular Transferases / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D007700:Kinetics; D011994:Recombinant Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity; D014539:Uridine Diphosphate Sugars / Q000378:metabolism*
chemical_list: D011994:Recombinant Proteins; D014539:Uridine Diphosphate Sugars; C040817:uridine diphosphate arabinose; D019751:Intramolecular Transferases