title: Characterization of beta-1,3-galactosyl-N-acetylhexosamine phosphorylase from Propionibacterium acnes.
abstract: Homologs of the beta-1,3-galactosyl-N-acetylhexosamine phosphorylase (GalHexNAcP) gene (gnpA) were cloned from the genomic DNA of Propionibacterium acnes JCM6425 and P. acnes JCM6473, showing 99.9% and 97.9% nucleotide sequence identity, respectively, with the ppa0083 gene from the genome-sequenced P. acnes KPA171202. No gnpA gene was detected in the genomic DNA of type strain P. acnes ATCC25746. The recombinant enzyme from P. acnes JCM6425 (GnpA) showed approximately 70 times higher specific activity of phosphorolysis on galacto-N-biose (Galbeta1-->3GalNAc, GNB) than that on lacto-N-biose I (Galbeta1-->3GlcNAc). K (m) value for GnpA on GNB was high, but GnpA did not exhibit activity on any derivatives of GNB examined. These results indicate that GnpA is GalHexNAcP which should be classified as galacto-N-biose phosphorylase. The large k (cat) value of GnpA on GalNAc suggests that GnpA would be a useful catalyst for the synthesis of GNB.
authors.affiliation: National Food Research Institute, National Agriculture and Food Research Organization, 2-1-12 Kannondai, Tsukuba, Ibaraki 305-8642, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakajima
authors.forename: Mamoru
authors.initials: M
authors.lastname: Nishimoto
authors.forename: Motomitsu
authors.initials: M
authors.lastname: Kitaoka
mesh_terms: D000117:Acetylglucosamine / Q000031:analogs & derivatives / Q000378:metabolism; D003001:Cloning, Molecular; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004187:Disaccharides / Q000378:metabolism; D004795:Enzyme Stability; D005700:Galactosyltransferases / Q000235:genetics* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D011425:Propionibacterium acnes / Q000201:enzymology* / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D013379:Substrate Specificity; D013696:Temperature
chemical_list: D004269:DNA, Bacterial; D004187:Disaccharides; C056853:6-O-galactopyranosylgalactose; C033398:galactosyl-1,3-N-acetylglucosamine; D005700:Galactosyltransferases; C118176:beta-1,3-galactosyl-N-acetylhexosamine phosphorylase; D000117:Acetylglucosamine