title: Identification of the putative proton donor residue of lacto-N-biose phosphorylase (EC 2.4.1.211).
abstract: Two lacto-N-biose phosphorylase (LNBP) isozyme genes were cloned from Bifidobacterium bifidum JCM1254. Alignment of the amino acid sequences of LNBP and its homologs identified 24 completely conserved acidic amino acid residues. All single mutants of Bifidobacterium longum LNBP at residues other than D313N retained considerable activity, suggesting that Asp313 is the putative proton donor residue in LNBP.
authors.affiliation: National Food Research Institute, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Nishimoto
authors.forename: Motomitsu
authors.initials: M
authors.lastname: Kitaoka
mesh_terms: D000596:Amino Acids; D001644:Bifidobacterium / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D017124:Conserved Sequence; D007527:Isoenzymes; D008969:Molecular Sequence Data; D009154:Mutation; D006005:Phosphorylases / Q000235:genetics* / Q000378:metabolism; D011522:Protons
chemical_list: D000596:Amino Acids; D007527:Isoenzymes; D011522:Protons; D006005:Phosphorylases