Identification of a sialate O-acetyltransferase from Campylobacter jejuni: demonstration of direct transfer to the C-9 position of terminalalpha-2, 8-linked sialic acid.
We have identified a sialate O-acetyltransferase in the lipo-oligosaccharide biosynthesis locus of Campylobacter jejuni. Strains possessing this locus are known to produce sialylated outer core structures that mimic host gangliosides, and have been implicated in triggering the onset of Guillain-Barré syndrome. The acetyltransferase, which was cloned and expressed as a fusion construct in Escherichia coli, is soluble and homologous with members of the NodL-LacA-CysE family of O-acetyltransferases. This enzyme catalyzes the transfer of O-acetyl groups onto oligosaccharide-bound sialic acid, with a high specificity for terminal alpha2,8-linked residues. The modification is directed to C-9 and not C-7 as is believed to occur more commonly in other organisms. Despite their wide prevalence and importance in both eukaryotes and prokaryotes, this is the first report to describe the characterization of a purified sialate O-acetyltransferase.
Institute for Biological Sciences, National Research Council Canada, Ottawa, Ontario K1A 0R6, Canada.
R Scott
RS
Houliston
Hubert P
HP
Endtz
Nobuhiro
N
Yuki
Jianjun
J
Li
Harold C
HC
Jarrell
Michiaki
M
Koga
Alex
A
van Belkum
Marie-France
MF
Karwaski
Warren W
WW
Wakarchuk
Michel
M
Gilbert
D000123:Acetyltransferases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D000595:Amino Acid Sequence; D016123:Campylobacter jejuni / Q000201:enzymology*; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D019158:N-Acetylneuraminic Acid / Q000737:chemistry / Q000378:metabolism*; D009844:Oligosaccharides / Q000378:metabolism*; D016366:Open Reading Frames; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D009844:Oligosaccharides; D011993:Recombinant Fusion Proteins; D000123:Acetyltransferases; D019158:N-Acetylneuraminic Acid