title: Arg276 of GseA, a Chlamydia trachomatis Kdo transferase, is required for the synthesis of the chlamydial genus-specific epitope in Escherichia coli.
abstract: GseA is an enzyme from Chlamydia trachomatis that can catalyse the addition of three 3-deoxy-D-manno-octulosonic acid (Kdo) residues onto lipid A precursors. GseA is similar, and in a few stretches identical, in its amino acid sequence to KdtA, an Escherichia coli Kdo transferase. In this study we altered an amino acid of GseA in a region that is identical between GseA and KdtA to test its importance in the structure or catalytic activity of GseA. We found that when Arg276 was changed to Lys, Ile or Ser, GseA activity was lost, suggesting an enzymatic role for this amino acid residue.
authors.affiliation: Canadian Bacterial Disease Network, University of Victoria, British Columbia, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Ekpo
authors.forename: F E
authors.initials: FE
authors.lastname: Nano
mesh_terms: D000595:Amino Acid Sequence; D001120:Arginine / Q000235:genetics*; D015153:Blotting, Western; D002240:Carbohydrate Sequence; D002692:Chlamydia trachomatis / Q000201:enzymology*; D003001:Cloning, Molecular; D000939:Epitopes / Q000235:genetics / Q000276:immunology*; D004926:Escherichia coli; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D016415:Sequence Alignment; D013400:Sugar Acids / Q000378:metabolism*; D014166:Transferases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000939:Epitopes; D013400:Sugar Acids; C002532:2-keto-3-deoxyoctonate; D001120:Arginine; D014166:Transferases; C019917:3-deoxy-D-manno-octulosonate transferase