title: Discovery of two β-1,2-mannoside phosphorylases showing different chain-length specificities from Thermoanaerobacter sp. X-514.
abstract: We characterized Teth514_1788 and Teth514_1789, belonging to glycoside hydrolase family 130, from Thermoanaerobacter sp. X-514. These two enzymes catalyzed the synthesis of 1,2-β-oligomannan using β-1,2-mannobiose and d-mannose as the optimal acceptors, respectively, in the presence of the donor α-d-mannose 1-phosphate. Kinetic analysis of the phosphorolytic reaction toward 1,2-β-oligomannan revealed that these enzymes followed a typical sequential Bi Bi mechanism. The kinetic parameters of the phosphorolysis of 1,2-β-oligomannan indicate that Teth514_1788 and Teth514_1789 prefer 1,2-β-oligomannans containing a DP ≥3 and β-1,2-Man2, respectively. These results indicate that the two enzymes are novel inverting phosphorylases that exhibit distinct chain-length specificities toward 1,2-β-oligomannan. Here, we propose 1,2-β-oligomannan:phosphate α-d-mannosyltransferase as the systematic name and 1,2-β-oligomannan phosphorylase as the short name for Teth514_1788 and β-1,2-mannobiose:phosphate α-d-mannosyltransferase as the systematic name and β-1,2-mannobiose phosphorylase as the short name for Teth514_1789.
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Chiku
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Nihira
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata, Japan.
authors.forename: Erika
authors.initials: E
authors.lastname: Suzuki
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Nishimoto
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan.
authors.forename: Motomitsu
authors.initials: M
authors.lastname: Kitaoka
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata, Japan.
authors.forename: Ken'ichi
authors.initials: K
authors.lastname: Ohtsubo
authors.affiliation: Faculty of Agriculture, Niigata University, Niigata, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakai
mesh_terms: D001483:Base Sequence; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D016000:Cluster Analysis; D017931:DNA Primers / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D006026:Glycoside Hydrolases / Q000235:genetics / Q000378:metabolism*; D007700:Kinetics; D008351:Mannans / Q000096:biosynthesis; D008362:Mannosides / Q000235:genetics / Q000378:metabolism*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D015394:Molecular Structure; D006005:Phosphorylases / Q000235:genetics / Q000378:metabolism*; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D013379:Substrate Specificity; D046968:Thermoanaerobacter / Q000201:enzymology* / Q000235:genetics
chemical_list: D017931:DNA Primers; D008351:Mannans; D008362:Mannosides; C043364:beta-1,2-mannopyranan; D006005:Phosphorylases; D006026:Glycoside Hydrolases