title: Characterization of α2,3- and α2,6-sialyltransferases from Helicobacter acinonychis.
abstract: Genome sequence data were used to clone and express two sialyltransferase enzymes of the GT-42 family from Helicobacter acinonychis ATCC 51104, a gastric disease isolate from Cheetahs. The deposited genome sequence for these genes contains a large number of tandem repeat sequences in each of them: HAC1267 (RQKELE)(15) and HAC1268 (EEKLLEFKNI)(13). We obtained two clones with different numbers of repeat sequences for the HAC1267 gene homolog and a single clone for the HAC1268 gene homolog. Both genes could be expressed in Escherichia coli and sialyltransferase activity was measured using synthetic acceptor substrates containing a variety of terminal sugars. Both enzymes were shown to have a preference for N-acetyllactosamine, and they each made a product with a different linkage to the terminal galactose. HAC1267 is a mono-functional α2,3-sialyltransferase, whereas HAC1268 is a mono-functional α2,6-sialyltransferase and is the first member of GT-42 to show α2,6-sialyltransferase activity.
authors.affiliation: National Research Council Canada, Institute for Biological Sciences, Ottawa, ON, Canada.
authors.forename: Melissa J
authors.initials: MJ
authors.lastname: Schur
authors.forename: Emilie
authors.initials: E
authors.lastname: Lameignere
authors.forename: Natalie C J
authors.initials: NC
authors.lastname: Strynadka
authors.forename: Warren W
authors.initials: WW
authors.lastname: Wakarchuk
mesh_terms: D000606:Amino Sugars / Q000737:chemistry; D001426:Bacterial Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D002236:Carbohydrate Conformation; D020134:Catalytic Domain; D003001:Cloning, Molecular; D006031:Glycosylation; D016998:Helicobacter / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D008274:Magnesium / Q000737:chemistry; D008345:Manganese / Q000737:chemistry; D008958:Models, Molecular; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D012794:Sialic Acids / Q000737:chemistry; D012799:Sialyltransferases / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics; D040681:Structural Homology, Protein; D013379:Substrate Specificity; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase
chemical_list: D000606:Amino Sugars; D001426:Bacterial Proteins; D011993:Recombinant Fusion Proteins; D012794:Sialic Acids; C000458:N-acetyllactosamine; D008345:Manganese; D012799:Sialyltransferases; D008274:Magnesium; D000094802:beta-D-Galactoside alpha 2-6-Sialyltransferase; D000094663:beta-Galactoside alpha-2,3-Sialyltransferase