Protein glycosylation is a ubiquitous post-translational modification present in all three kingdoms of life. In prokaryotes, glycans are frequently present on extracellular proteins to engage in host-microbe interactions. Glycans are also found inside the cell, where they help modulate bacterial homeostasis by tuning protein function. Notably, bacteria utilize a large variety of carbohydrate moieties and linkages, many of which are not found in eukaryotic systems. One such example is the recently reported arginine-rhamnose motif detected in a protein from Pseudomonas aeruginosa , a previously unprecedented modification in both bacteria and eukaryotes. Rhamnose is transferred from TDP-L-Rha to a specific arginine by the action of the glycosyltransferase EarP (Fig.1). The rhamnosylated arginine motif is essential for bacterial protein biosynthesis and is predicted to be conserved in a number of bacterial pathogens.
In this talk I will describe our efforts towards understanding the key recognition elements of the bacterial protein glycosyltransferase EarP. By employing enzyme activity assays, substrate mimics, and NMR techniques we aim to expand the knowledge of bacterial glycosyltransferases as a first step to targeted inhibitor design against clinically relevant gram-negative pathogens.
- Lassak, J.; Keilhauer, E.C.; Fürst, M.; Wuichet, K.; Gödeke, J.; Starosta, A.L.; Chen, J-M.; Søgaard-Andersen, L.; Rohr, J.; Wilson, D.N.; Häussler, S.; Mann, M.; Jung, K. Arginine-rhamnosylation as new strategy to activate translation elongation factor P. Nat. Chem. Biol. 2015, 11, 266-270.