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The cell wall of the oral bacterium Streptococcus mutans carries SCC, a rhamnose-containing polysaccharide with glucose side-chain decorations. Here, the authors report the SCC structure and the synthesis mechanism, revealing how four glucosyltransferases work together to synthesize the side-chains.

Identification of host antiviral restriction factors could provide targets for antiviral therapy. Here, using a genome-wide CRISPR screen, the authors identify the glycosyltransferase B3GAT1 as a host protein which, when ectopically overexpressed, restricts influenza virus infection in vitro and in mice, as well as other viruses relying on sialic acid for entry.

Proteoglycans are glycosylated proteins that play a number of structural and signalling functions. Here, Corti, Wang et al. show that the N-terminal sequence of proteoglycan Syndecan-2 selectively increases 6-O sulfation of its heparan sulfate chains, and that this promotes formation of a ternary Sdc2/VEGFA/VEGFR2 complex leading to increased angiogenesis.

Fucosylation of host glycoproteins is revealed to sensitize cells to cholera intoxication while fucosylation of host glycolipids is protective. The glycosyltransferases encoded by B3GALT5 and B3GNT5 are identified as key regulators of this phenomenon.

1,3-Pr2-6-OTs GlcNAlk is a precursor uniquely targeting the essential glycosyltransferase MGAT1 to selectively tag hybrid N-glycan-modified proteins. Some hybrid-glycan tagged proteins move through a route from the Golgi to the nucleus/nucleolus.

N-linked glycoprotein production requires attachment of eukaryotic glycans to eukaryotic proteins. The introduction of four eukaryotic glycosyltransferases and a bacterial oligosaccharyltransferase now allows E. coli to produce and transfer a five-glycan Man₃GlcNAc₂ eukaryotic core structure to several protein targets.

Chlamydomonas reinhardtii produces a glycoprotein-rich cell wall. Using nuclear magnetic resonance and mass spectrometry approaches, this study reveals unprecedented details on its protein and carbohydrate content, and provide an atomic-level architecture model.

In this study, Giron et al. find that people living with chronic HIV experience accelerated aging-associated alterations in antibody glycans. These alterations, attributed to senescence enzymes, predict comorbidities and reduce the antiviral function of antibodies.

Increased susceptibility to gastrointestinal infections and colitis can be driven by a failure to maintain intestinal homeostasis. Here, using a forward genetic screen, Song et al. identify and characterise the role of TVP23B in Paneth cell and goblet cell function, and its impact on colitis.

Exopolysaccharides (EPS) are perceived by legumes and regulate symbiosis with rhizobia. Here the authors describe the structure of the Lotus EPS receptor, EPR3 and show that it has atypical βαββ and βαβ folds that represent a structural signature for a unique class of EPS receptors in the plant kingdom.

Gram negative microbes strategically equip lipopolysaccharides with O antigens to expand the extracellular envelope. Here, the authors examine how the O antigen is captured by a special class of ABC transporters containing a carbohydrate-binding module accessory.

Mucus are ubiquitous natural materials, but little is known about their structures or properties. Here, the authors identify the components of three functional mucus from snails, which are the focus of a rapidly growing number of biomedical and cosmetic applications.

An orthogonal O-glycan biosynthesis system was engineered in Escherichia coli to support the production of glycoproteins displaying human mucin O-glycans, including Tn antigens, in living bacteria and in cell-free extracts.

Accurate NMR shift prediction using machine learning allows researchers to validate structures by comparing predicted and observed shifts, but predicting 2D NMR remains challenging due to limited annotated data. Here, the authors introduce an unsupervised training framework for predicting and annotating cross-peaks in 2D NMR considering solvent effect, specifically Heteronuclear Single Quantum Coherence (HSQC), showing a MAE of 2.05 ppm for ¹³C and 0.165 ppm for ¹H, and achieving 95.21% concordance with experts’ assignments.

Pregnancy-induced post-translational antibody modification enables protection against the prototypical intracellular pathogen Listeria monocytogenes.

Aspergillus fumigatus is a pathogenic fungus. Here the authors perform solid-state NMR measurements with intact Aspergillus cells, which provides insights into cell wall composition and dynamics and propose a structural model for fungal cell walls.

Pneumocystis jirovecii is a fungus that can cause life-threatening pneumonia in immunocompromised patients. Here, the authors sequence the genomes of P. jirovecii and two other Pneumocystisspecies, and show the unexpected absence of chitin (a near universal fungal cell wall component).

Cultivation of a cellulolytic consortium reveals successional community dynamics and the presence of multidomain glycoside hydrolases assembled into stable complexes distinct from cellulosomes, which are produced by a potential pioneer population.

Many pathogenic bacteria have evolved to subvert host immune responses triggered by lipopolysaccharides (LPS). Here the authors show that a long terminal polysaccharide chain, known as the O-antigen, present in LPS from the plant pathogen Xylella fastidiosa can delay recognition by grapevine hosts.

Fluorinated, cell-permeable analogs of sialic acid and fucose are processed by monosaccharide salvage pathways to generate sialyl- and fucosyltransferase inhibitors intracellularly. These compounds serve as important new tools to dissect the role of glycan modifications within complex biological systems.

A library of mutant mouse lung endothelial cells expressing a comprehensive repertoire of heparin sulfate structure modifications enables studies of the structure–function relationships of this complex polysaccharide.

Garber et al. solved the structure of the fucose dehydrogenase FucX of the gastrointestinal pathogen Campylobacter jejuni. Although C. jejuni lacks fucosidases and prefers amino acids to carbohydrates, Bacteroides vulgatus enhances the growth of C. jejuni in vitro in the presence of mucin, suggesting that this pathogen may obtain sugars from the commensal microbiota.