Browsing by Author "Benedyk, Tomasz Henryk"

Yersinia enterocolitica is an important model organism for gram-negative virulent bacteria. It is also a causative agent of yersiniosis, a common infectious disease related mostly to gastroenteritis, with the serotype O:3 (Ye O:3) being diagnosed in most cases. The lipopolysaccharide (LPS) of Ye O:3 comes with many peculiarities, and with the temperature-regulated formation of its components (e.g O-antigen) being the most remarkable. This interplay between the bacteria and their surrounding environment serves as a good platform to investigate the molecular mechanisms involved in both sensing and responding to the changes. In our study, we looked for the best gene candidates taking part in the O-antigen temperature-regulation based on the RNAseq data, and consequently we tried to reveal the metabolic pathways possibly shaping up the O-antigen structure. Our initial findings helped us formulate a hypothesis about internal competition between the LPS constituents for the common intermediates. Different availability of some of those precursors, namely UPD-N-acetyl-D-glucosamine and its lipid carrier – undecaprenyl phosphate, at different temperatures, would trigger the observed alternations in the O-antigen abundancy. Indeed, our functional assay using the overexpression strain grown in defined media, confirmed a reversible shortage of at least one of those two precursor molecules required for the O-antigen assembly in the bacteria grown at 37 degrees Celsius.