The Sweet Tooth of Bacteria: Common Themes in Bacterial Glycoconjugates

Abstract

SUMMARY Humans have been increasingly recognized as being superorganisms, living in close contact with a microbiota on all their mucosal surfaces. However, most studies on the human microbiota have focused on gaining comprehensive insights into the composition of the microbiota under different health conditions (e.g., enterotypes), while there is also a need for detailed knowledge of the different molecules that mediate interactions with the host. Glycoconjugates are an interesting class of molecules for detailed studies, as they form a strain-specific barcode on the surface of bacteria, mediating specific interactions with the host. Strikingly, most glycoconjugates are synthesized by similar biosynthesis mechanisms. Bacteria can produce their major glycoconjugates by using a sequential or an en bloc mechanism, with both mechanistic options coexisting in many species for different macromolecules. In this review, these common themes are conceptualized and illustrated for all major classes of known bacterial glycoconjugates, with a special focus on the rather recently emergent field of glycosylated proteins. We describe the biosynthesis and importance of glycoconjugates in both pathogenic and beneficial bacteria and in both Gram-positive and -negative organisms. The focus lies on microorganisms important for human physiology. In addition, the potential for a better knowledge of bacterial glycoconjugates in the emerging field of glycoengineering and other perspectives is discussed.

Insights into bacterial protein glycosylation in human microbiota

“…The major modification on Campylobacter flagellin is O-linked pseudaminic acid (Thibault et al, 2001). Since the glycosylation of flagella has been reviewed recently (Tytgat and Lebeer, 2014), we will not expand on this topic. C. jejuni harbors both O- and N-linked glycosylation system, each has a dedicated gene cluster to catalyze the modification (Day et al, 2012; Guerry and Szymanski, 2008; Szymanski et al, 2003).…”

“…The key to better understanding the interaction is the identification and characterization of the molecular players present on the bacterial cell surface, often are glycoconjugates such as surface glycosylated proteins (adhesins), exopolysaccharides (EPSs), capsular polysaccharides (CPSs), lipopolysaccharides (LPSs), and peptidoglycan (PG) etc. (Reviewed in (Tytgat and Lebeer, 2014)). In this review, we will focus on one of the glycoconjugates—surface glycoproteins.…”

Mycoplasma agalactiae Secretion of β-(1→6)-Glucan, a Rare Polysaccharide in Prokaryotes, Is Governed by High-Frequency Phase Variation

“…13 C NMR experiments were conducted using the same spectrometer operating at 125.48 MHz with 2 s as the relaxation delay. The two-dimensional (2D) 1 Detection of polysaccharide secretion by colony immunostaining. Colony immunostaining experiments were performed as described previously (24).…”

Covalent inhibitors of LgtC: A blueprint for the discovery of non-substrate-like inhibitors for bacterial glycosyltransferases

“…Many of the bacterial GTs that are amenable to this general inhibitor discovery strategy are involved in bacterial virulence processes and complex pathogen/host interactions [31]. Covalent inhibitors would therefore be eminently useful as tool compounds for anti-virulence drug discovery [32], not only for inhibition studies, but also as affinity probes for the labelling and imaging of bacterial GTs in vivo.…”