Metabolic Labeling of Legionaminic acid in Flagellin Glycosylation of Campylobacter jejuni Identifies Maf4 as a Putative Legionaminyl Transferase

Campylobacter jejuni is the major human food-borne pathogen. Its bipolar flagella are heavily O-glycosylated with microbial sialic acids and essential for its motility pathogenicity. However, both glycosylation of exact contribution legionaminic acid (Leg) to flagellar activity poorly understood. Herein, we report development a metabolic labeling method Leg on bacterial probes based azide-modified precursors. The hereby azido-Leg labeled flagellin could be detected by Western blot analysis imaged intact bacteria. Using C. isogenic maf4 mutant also further substantiated identification Maf4 as putative glycosyltransferase. Further evidence was provided UPLC–MS detection CMP-Leg an in silico model Maf4. This developed will facilitate study functional role this modification invasiveness.