Functional genomics of Helicobacter pylori: identification of a beta-1,4 galactosyltransferase and generation of mutants with altered lipopolysaccharide.
A previously annotated open reading frame (ORF) (HP0826) from Helicobacter pylori was cloned and expressed in Escherichia coli cells and determined to be a beta-1,4-galactosyltransferase that used GlcNAc as an acceptor. Mutational analysis in H. pylori strains demonstrated that this enzyme plays a key role in the biosynthesis of the type 2 N-acetyl-lactosamine (LacNAc) polysaccharide O-chain backbone, by catalysing the addition of Gal to GlcNAc. To examine the potential role of this O-chain structure in bacterial colonization of the host stomach, the mutation was introduced into H. pylori strain SS1 which is known to be capable of colonizing the gastric mucosa of mice. Compared with the parental strain, mutated SS1 was less efficient at colonizing the murine stomach.
Logan
S M
SM
Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada, K1A OR6. susan.logan@nrc.ca
Conlan
J W
JW
Monteiro
M A
MA
Wakarchuk
W W
WW
Altman
E
E
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002240:Carbohydrate Sequence; D017931:DNA Primers; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D016680:Genome, Bacterial; D016481:Helicobacter Infections / Q000201:enzymology / Q000378:metabolism / Q000382:microbiology; D016480:Helicobacter pylori / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D008070:Lipopolysaccharides / Q000737:chemistry / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009237:N-Acetyllactosamine Synthase / Q000737:chemistry / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D016339:Spectrometry, Mass, Fast Atom Bombardment; D013270:Stomach / Q000382:microbiology
D017931:DNA Primers; D008070:Lipopolysaccharides; D009237:N-Acetyllactosamine Synthase