Carbohydrates

  • Article
    | Open Access

    Here, Broszeit et al. show that circulating A/H3N2 viruses have evolved binding specificity to α2,6-sialosides on extended LacNAc moieties and therefore cannot agglutinate erythrocytes. Applying glycan remodeling allows to install functional receptors on erythrocytes and promotes identification of newly circulating variants to facilitate vaccine design.

    • Frederik Broszeit
    • , Rosanne J. van Beek
    •  & Geert-Jan Boons
  • Article
    | Open Access

    O-GalNAc glycans are essential in many biological and pathological processes, but difficult to access due to their structural complexity and synthetic challenges. Here, the authors report an efficient chemoenzymatic modular assembly strategy to construct structurally diverse O-GalNAc glycans, use the synthesised glycans to generate a synthetic mucin O-glycan microarray and profile binding specificities of glycan-binding proteins.

    • Shuaishuai Wang
    • , Congcong Chen
    •  & Lei Li
  • Article
    | Open Access

    Microbial oxidoreductases are key in biomass breakdown. Here, the authors expand the specificity and redox scope within fungal auxiliary activity 7 family (AA7) enzymes and show that AA7 oligosaccharide dehydrogenases can directly fuel cellulose degradation by lytic polysaccharide monooxygenases.

    • Majid Haddad Momeni
    • , Folmer Fredslund
    •  & Maher Abou Hachem
  • Article
    | Open Access

    Exolytic heparinases are needed for sequencing of heparin and heparan sulfate (HP), but have not yet been reported. Here, the authors identify exolytic heparinases from different bacteria and show that the heparinases preferentially digest HP, determine the crystal structure of the exoheparinase BlexoHep and perform sequencing of HP octasaccharides using the enzyme.

    • Qingdong Zhang
    • , Hai-Yan Cao
    •  & Fuchuan Li
  • Article
    | Open Access

    The fate of ocean carbon is determined by the balance between primary productivity and heterotrophic breakdown of that photosynthate. Here the authors show that diatoms produce a polysaccharide that resists bacterial degradation, accumulates, aggregates and stores carbon during spring blooms.

    • Silvia Vidal-Melgosa
    • , Andreas Sichert
    •  & Jan-Hendrik Hehemann
  • Article
    | Open Access

    Lipopolysaccharides, important components of the bacterial cell envelope, are synthesized at the inner membrane by the Wzx/Wzy-dependent assembly pathway. A cryo-EM structure of an intact E. coli WzzB, the polysaccharide co-polymerase component of this pathway, reveals details of the transmembrane, cytoplasmic domains and a conserved a proline-rich segment proximal to the C-terminal transmembrane helix.

    • Benjamin Wiseman
    • , Ram Gopal Nitharwal
    •  & Martin Högbom
  • Article
    | Open Access

    C-nucleosides are analogues of the canonical N-nucleosides and, despite their synthetic value, biocatalysis has not targeted them yet. Here, the authors report a pseudouridine monophosphate C-glycosidase enzyme for selective 5-β-C-glycosylation of uracil and its derivatives from pentose 5- phosphate substrates.

    • Martin Pfeiffer
    •  & Bernd Nidetzky
  • Article
    | Open Access

    Myo-Inositol phosphates (InsPs) and pyrophosphates (PP-InsPs) are important second messengers but their analysis remains challenging. Here, the authors develop a capillary electrophoresis-mass spectrometry method for the identification and quantitation of InsP and PP-InsP isomers in cells and tissues.

    • Danye Qiu
    • , Miranda S. Wilson
    •  & Henning J. Jessen
  • Article
    | Open Access

    C-glycosides are of pharmaceutical interest due to their stability against in vivo hydrolysis, however their enzymatic synthesis faces challenges. Here, the authors report a C-glycosyltransferase from Aloe barbadensis catalysing the C-glycosylation of drug-like acceptors to generate bioactive C-glycosides.

    • Kebo Xie
    • , Xiaolin Zhang
    •  & Jungui Dai
  • Article
    | Open Access

    Sialic acid-binding immunoglobulin-type lectins (Siglecs) are a family of immunomodulatory receptors expressed on cells of the hematopoietic lineage. Here the authors demonstrate an approach for the identification of the glycan ligands of Siglecs, which is also applicable to other families of glycan-binding proteins.

    • Emily Rodrigues
    • , Jaesoo Jung
    •  & Matthew S. Macauley
  • Article
    | Open Access

    Neisseria meningitidis capsular polysaccharide (CPS) is a major virulence factor and vaccine formulations against Neisseria meningitidis serogroup A (NmA) contain O-acetylated CPS. Here, the authors provide mechanistic insights into CPS O-acetylation in NmA by determining the crystal structure of the O-acetyltransferase CsaC and NMR measurements further reveal that the CsaC-mediated reaction is regioselective for O3 and that the O4 modification results from spontaneous O-acetyl migration.

    • Timm Fiebig
    • , Johannes T. Cramer
    •  & Martina Mühlenhoff
  • Article
    | Open Access

    Hemicelluloses are an essential constituent of plant cell walls, but the individual biomechanical roles remain elusive. Here the authors report on the interaction of wood hemicellulose with bacterial cellulose during deposition and explore the resultant fibrillar architecture and mechanical properties.

    • Jennie Berglund
    • , Deirdre Mikkelsen
    •  & Francisco Vilaplana
  • Article
    | Open Access

    Glycans are abundant biomolecules that mediate essential biological processes, but their chemical synthesis is challenging. Here, the authors report the synthesis of glycans up to a 128-mer, which represents the O-antigen of Bacteroides vulgatus lipopolysaccharide and one of the longest synthetic glycans to date.

    • Qian Zhu
    • , Zhengnan Shen
    •  & Biao Yu
  • Article
    | Open Access

    While mass spectrometry-based proteomics largely relies on digesting proteins into peptides, there is no equivalent strategy for polysaccharide analysis. Here, the authors develop a chemical approach to break down poly- into oligosaccharides and present a workflow to identify polysaccharides by oligosaccharide fingerprinting.

    • Matthew J. Amicucci
    • , Eshani Nandita
    •  & Carlito B. Lebrilla
  • Article
    | Open Access

    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.

    • Jaslyn E. M. M. Wong
    • , Kira Gysel
    •  & Kasper R. Andersen
  • Article
    | Open Access

    Bioproduction of hyaluronan needs increases in yield and greater diversity of the molecular weights. Here, the author increases hyaluronan production and diversifies the molecular weights through engineering the hyaluronan biosynthesis pathway and disruption of Corynebacterium glutamicum encapsulation caused by secreted hyaluronan.

    • Yang Wang
    • , Litao Hu
    •  & Zhen Kang
  • Article
    | Open Access

    Trefoil factors (TFFs) protect the mucosa and have various reported binding activities, but whether they share a common interaction mechanism has remained unclear. Here, the authors provide structural and biochemical evidence that all three human TFFs are divalent lectins that recognise the same disaccharide.

    • Michael A. Järvå
    • , James P. Lingford
    •  & Ethan D. Goddard-Borger
  • Article
    | Open Access

    Heparan sulfates (HS) contain functionally relevant structural motifs, but determining their monosaccharide sequence remains challenging. Here, the authors develop an ion mobility mass spectrometry-based method that allows unambiguous characterization of HS sequences and structure-activity relationships.

    • Rebecca L. Miller
    • , Scott E. Guimond
    •  & Kevin Pagel
  • Article
    | Open Access

    Core-fucosylation of the N-glycan core is an essential biological modification and the α1,6- fucosyltransferase FUT8 is the only enzyme in humans that catalyses this modification through the addition of an α-1,6-linked fucose to N-glycans. Here the authors provide insights into FUT8 substrate recognition by determining the 1.95 Å crystal structure of human FUT8 complexed with GDP and a biantennary complex N-glycan.

    • Ana García-García
    • , Laura Ceballos-Laita
    •  & Ramon Hurtado-Guerrero
  • Article
    | Open Access

    Metabolic adaptation to different diets results in changes to gene expression. Here, the authors characterise the chromatin landscape and transcriptional network in mice on a diet of high saturated fat, compared to a diet high in carbohydrate, finding a dramatic reprogramming of the liver transcriptional network.

    • Yufeng Qin
    • , Sara A. Grimm
    •  & Paul A. Wade
  • Article
    | Open Access

    Glycosaminoglycans (GAGs) are an important nutrient source for the gut microbiome. Here, the authors characterize the genetic loci that underpins glycosaminoglycan utilization in Bacteroides thetaiotaomicron; providing insights into the metabolism of GAGs by a predominant member of the gut microbiota.

    • Didier Ndeh
    • , Arnaud Baslé
    •  & Alan Cartmell
  • Article
    | Open Access

    Fukutin-related protein (FKRP) catalyses the addition of ribitol-phosphate (RboP) to the O-mannosyl glycan of α-dystroglycan and mutations in FKRP cause dystroglycanopathy. Here the authors provide insights into its oligomerization and recognition of the substrates, CDP-Rbo and the RboP-(phospho-)core M3 glycan, by determining the crystal structures of human FKRP.

    • Naoyuki Kuwabara
    • , Rieko Imae
    •  & Ryuichi Kato
  • Article
    | Open Access

    Understanding the interactions between the constituents of the cell walls in wood is important for understanding the mechanical properties. Here, the authors report on a solid-state NMR study of never-dried softwood, noticing differences to previous reports and develop a model of softwood architecture.

    • Oliver M. Terrett
    • , Jan J. Lyczakowski
    •  & Paul Dupree
  • Article
    | Open Access

    Sialidases are glycoside hydrolases that cleave sialosides. Here the authors define the 3-D structure, alone and in complex with products and inhibitors, of the CAZy family GH156 sialidase, EnvSia156, showing it displays a catalytical (β/α) 8-barrel domain distinct from other sialidases and allowing description of its inverting catalytic mechanism.

    • Pedro Bule
    • , Léa Chuzel
    •  & Gideon J. Davies
  • Article
    | Open Access

    Bacterial growth and division require remodelling of the cell wall, which generates free peptidoglycan fragments. Here, Moynihan et al. show that Mycobacterium tuberculosis can recycle components of their peptidoglycan, and characterise a crucial enzyme required for this process.

    • Patrick J. Moynihan
    • , Ian T. Cadby
    •  & Gurdyal S. Besra
  • Article
    | Open Access

    In-depth characterization of complex glycomes is complicated by the immense structural diversity of glycans. Here, the authors present a mass spectrometry-based strategy for untargeted, sensitive glycan profiling and identify 167 N-glycan compositions in total human plasma.

    • Guinevere S. M. Lageveen-Kammeijer
    • , Noortje de Haan
    •  & Manfred Wuhrer
  • Article
    | Open Access

    Bacteroidetes genomes contain polysaccharide utilization loci (PULs), each of which encodes enzymes for the breakdown of one particular glycan. By analyzing the enzyme composition of 13,537 PULs, the authors suggest that the natural glycan diversity is orders of magnitude lower than previously proposed.

    • Pascal Lapébie
    • , Vincent Lombard
    •  & Bernard Henrissat
  • Article
    | Open Access

    Proteins continuously undergo non-enzymatic modifications such as glycation, which accumulate under physiological conditions but can be enhanced in disease. Here the authors characterise histone glycation, provide evidence that it affects chromatin, particularly in breast cancer, and identify DJ-1 as a deglycase.

    • Qingfei Zheng
    • , Nathaniel D. Omans
    •  & Yael David
  • Article
    | Open Access

    How dietary β-mannans are utilized by gut Gram-positive bacteria is unclear. Here, the authors uncover the enzymatic pathway for β-mannan metabolism in Roseburia intestinalis and show that these polysaccharides promote beneficial gut bacteria, highlighting a potential for β-mannan-based therapeutic interventions.

    • Sabina Leanti La Rosa
    • , Maria Louise Leth
    •  & Bjørge Westereng
  • Article
    | Open Access

    Mother Nature is a valuable resource for the discovery of drug and agricultural chemicals. Here, the authors show that 7-deoxy-sedoheptulose produced by a cyanobacterium is an antimicrobial and herbicidal compound that acts through inhibition of 3-dehydroquniate synthase in the shikimate pathway.

    • Klaus Brilisauer
    • , Johanna Rapp
    •  & Karl Forchhammer
  • Article
    | Open Access

    Plants are dependent on controlled sugar uptake via Monosaccharide Transporters, such as STP10, for correct organ development, sugar accumulation in fruits and microbial defense. Here authors present the crystal structure of STP10 bound to glucose which sheds light on the fundamental principles of sugar transport in the plant-unique MST superfamily.

    • Peter Aasted Paulsen
    • , Tânia F. Custódio
    •  & Bjørn Panyella Pedersen
  • Article
    | Open Access

    The interactions of lignin with polysaccharides in plant secondary cell walls are not well understood. Here the authors employ solid-state NMR measurements to analyse intact stems of maize, Arabidopsis, switchgrass and rice and observe that lignin self-aggregates and forms highly hydrophobic microdomains that make extensive surface contacts to xylan.

    • Xue Kang
    • , Alex Kirui
    •  & Tuo Wang
  • Article
    | Open Access

    The glycome of parasites can have immunomodulatory properties or help to avoid immune surveillance, but details are unknown. Here, Martini et al. characterize the N-glycome of the canine heartworm, reveal an unprecedented complexity, particularly in anionic N-glycans, and determine recognition by components of the immune system.

    • Francesca Martini
    • , Barbara Eckmair
    •  & Katharina Paschinger
  • Article
    | Open Access

    The software Optimer has aided the programmable one-pot oligosaccharide synthesis with a library of 50 Building BLocks (BBLs). Here, the authors expanded Optimer's validated and virtual libraries of BBLs and developed Auto-CHO, a software which allows the one-pot programmable synthesis of more complex glycans.

    • Cheng-Wei Cheng
    • , Yixuan Zhou
    •  & Chi-Huey Wong
  • Article
    | Open Access

    Marine woodborers can digest woody biomass without the help of gut microbiota but the mechanism has remained unclear. Here, the authors provide evidence that the woodborer’s respiratory protein hemocyanin plays a central role in wood digestion and may offer a route toward biorefining of woody plant biomass.

    • Katrin Besser
    • , Graham P. Malyon
    •  & Simon J. McQueen-Mason
  • Article
    | Open Access

    Bacillus anthracis causes the infectious disease anthrax. Here, the authors synthesized deoxy glycosides that are effective against B. anthracis and related bacteria and found that these amphiphilic compounds kill bacteria via an unusual mechanism of action.

    • Catarina Dias
    • , João P. Pais
    •  & Amélia P. Rauter
  • Article
    | Open Access

    Polyfluorinated hexopyranoses display unique physical, chemical and biological properties, however their stereoselective synthesis is highly challenging. Here, the authors report a synthetic approach based on the chemical manipulation of inexpensive levoglucosan to obtain heavily fluorinated monosaccharides stereoselectively.

    • Vincent Denavit
    • , Danny Lainé
    •  & Denis Giguère
  • Article
    | Open Access

    Human rotaviruses (RV) bind to histo-blood group antigens (HBGA) for attachment, but how different viral genotypes interact with HBGA isn’t known. Here, Hu et al. report crystal structures of a prevalent and a neonate-specific RV in complex with HBGA and provide insights into glycan recognition and age-restricted tropism of RVs.

    • Liya Hu
    • , Banumathi Sankaran
    •  & B. V. Venkataram Prasad
  • Article
    | Open Access

    Cellobiohydrolases (CBHs) are critical for natural and industrial biomass degradation but their structure–activity relationships are not fully understood. Here, the authors present the biochemical and structural characterization of two CBHs, identifying protein regions that confer enhanced CBH activity.

    • Larry E. Taylor II
    • , Brandon C. Knott
    •  & Gregg T. Beckham
  • Article
    | Open Access

    Polysaccharides are the primary structural cell wall and energy storage molecules of seaweed. Here, the authors show how the geographically restricted dietary polysaccharide agarose is selectively utilized by the human intestinal bacterium Bacteroides uniformis, providing insight into how carbohydrate metabolism evolves within the human microbiome.

    • Benjamin Pluvinage
    • , Julie M. Grondin
    •  & D. Wade Abbott
  • Article
    | Open Access

    Glycans, interaction platforms protruding from the surface of cells, are hard to study due to their diverse architecture. Here, the authors present a method to obtain cells carrying defined glycans, which can then be used to find proteins specifically recognizing these tags.

    • Jennie Grace Briard
    • , Hao Jiang
    •  & Peng Wu
  • Article
    | Open Access

    LPMOs catalyze the oxidative breakdown of polysaccharides, thereby facilitating biomass degradation. By analyzing the digestive proteome of firebrats, the authors here identify a yet uncharacterized LPMO family and provide phylogenetic, structural and biochemical insights into its origin and functions.

    • Federico Sabbadin
    • , Glyn R. Hemsworth
    •  & Simon J. McQueen-Mason