title: Cloning and characterization of the l-ribose isomerase gene from Cellulomonas parahominis MB426.
abstract: A newly isolated bacterium, Cellulomonas parahominis MB426, produced l-ribose isomerase (CeLRI) on a medium containing l-ribose as a sole carbon source. A 32 kDa protein isomerizing l-ribose to l-ribulose was purified to homogeneity from this bacterium. A set of degenerated primers were synthesized based on amino acid sequences of the purified CeLRI, and a 747 bp gene encoding CeLRI was cloned, sequenced and overexpressed in Escherichia coli. This gene encoded a 249 amino acid protein with a calculated molecular mass of 27,435. The deduced amino acid sequence of this gene showed the highest identity with l-ribose isomerase from Acinetobacter calcoaceticus DL-28 (71%). The recombinant l-ribose isomerase (rCeLRI) was optimally active at pH 9.0 and 40°C, and was stable up to 40°C for 1 h and not dependent for metallic ions for its activity. The rCeLRI showed widely substrate specificity for the rare sugar which involved l-erythro form such as l-ribose, d-lyxose, d-talose, d-mannose, l-gulose, and l-allose.
authors.affiliation: Rare Sugar Research Center, Kagawa University, Miki-cho, Kagawa, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Morimoto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Terami
authors.forename: Yu-ichiro
authors.initials: Y
authors.lastname: Maeda
authors.forename: Akihide
authors.initials: A
authors.lastname: Yoshihara
authors.forename: Goro
authors.initials: G
authors.lastname: Takata
authors.forename: Ken
authors.initials: K
authors.lastname: Izumori
mesh_terms: D019747:Aldose-Ketose Isomerases / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D040143:Cellulomonas / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006601:Hexoses / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D008969:Molecular Sequence Data; D010429:Pentoses / Q000378:metabolism; D012266:Ribose / Q000235:genetics / Q000378:metabolism; D013379:Substrate Specificity
chemical_list: D006601:Hexoses; D010429:Pentoses; C057406:gulose; C100182:ribulose; C002055:allose; C043333:lyxose; D012266:Ribose; D019747:Aldose-Ketose Isomerases; C022546:ribose isomerase; D005947:Glucose; D008358:Mannose