Genetics behind the Biosynthesis of Nonulosonic Acid-Containing Lipooligosaccharides in Campylobacter coli.

and are the most common causes of bacterial gastroenteritis in the world. Ganglioside mimicry by lipooligosaccharide (LOS) is the triggering factor of Guillain-Barré syndrome (GBS), an acute polyneuropathy. Sialyltransferases from glycosyltransferase family 42 (GT-42) are essential for the expression of ganglioside mimics in Recently, two novel GT-42 genes, and , have been identified in Despite being present in ∼11% of currently available genomes, the biological role of and is unknown. In the present investigation, mutation studies with two strains expressing either or were performed and mass spectrometry was used to investigate differences in the chemical composition of LOS. Attempts were made to identify donor and acceptor molecules using activity tests with recombinant GT-42 enzymes. Here we show that CstIV and CstV are involved in LOS biosynthesis. In particular, is associated with LOS sialylation, while is linked to the addition of a diacetylated nonulosonic acid residue. Despite the fact that a major foodborne pathogen, its glycobiology has been largely neglected. The genetic makeup of the lipooligosaccharide biosynthesis locus was largely unknown until recently. harbors a large set of genes associated with lipooligosaccharide biosynthesis, including genes for several putative glycosyltransferases involved in the synthesis of sialylated lipooligosaccharide in In the present study, was found to express lipooligosaccharide structures containing sialic acid and other nonulosonate acids. These findings have a strong impact on our understanding of ecology, host-pathogen interaction, and pathogenesis.