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N-glycosylation of a cargo protein C-terminal domain recognized by the type IX secretion system in Cytophaga hutchinsonii affects protein secretion and localization. Appl Environ Microbiol 2021; 88:e0160621. [PMID: 34644163 DOI: 10.1128/aem.01606-21] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cytophaga hutchinsonii is a Gram-negative bacterium belonging to the phylum Bacteroidetes. It digests crystalline cellulose with an unknown mechanism, and possesses a type IX secretion system (T9SS) that can recognize the C-terminal domain (CTD) of the cargo protein as a signal. In this study, the functions of CTD in the secretion and localization of T9SS substrates in C. hutchinsonii were studied by fusing the green fluorescent protein (GFP) with CTD from CHU_2708. CTD is necessary for the secretion of GFP by C. hutchinsonii T9SS. The GFP-CTDCHU_2708 fusion protein was found to be glycosylated in the periplasm with a molecular mass about 5 kDa higher than that predicted from its sequence. The glycosylated protein was sensitive to peptide-N-glycosidase F which can hydrolyze N-linked oligosaccharides. Analyses of mutants obtained by site-directed mutagenesis of asparagine residues in the N-X-S/T motif of CTDCHU_2708 suggest that N-glycosylation occurred on the CTD. CTD N-glycosylation is important for the secretion and localization of GFP-CTD recombinant proteins in C. hutchinsonii. Glycosyltransferase encoding gene chu_3842, a homologous gene of Campylobacter jejuni pglA, was found to participate in the N-glycosylation of C. hutchinsonii. Deletion of chu_3842 affected cell motility, cellulose degradation, and cell resistance to some chemicals. Our study provided the evidence that CTD as the signal of T9SS was N-glycosylated in the periplasm of C. hutchinsonii. IMPORTANCE The bacterial N-glycosylation system has previously only been found in several species of Proteobacteria and Campylobacterota, and the role of N-linked glycans in bacteria is still not fully understood. C. hutchinsonii has a unique cell-contact cellulose degradation mechanism, and many cell surface proteins including cellulases are secreted by the T9SS. Here, we found that C. hutchinsonii, a member of the phylum Bacteroidetes, has an N-glycosylation system. Glycosyltransferase CHU_3842 was found to participate in the N-glycosylation of C. hutchinsonii proteins, and had effects on cell resistance to some chemicals, cell motility, and cellulose degradation. Moreover, N-glycosylation occurs on the CTD translocation signal of T9SS. The glycosylation of CTD apears to play an important role in affecting T9SS substrates transportation and localization. This study enriched our understanding of the widespread existence and multiple biological roles of N-glycosylation in bacteria.
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Thomas C, Nothaft H, Yadav R, Fodor C, Alemka A, Oni O, Bell M, Rada B, Szymanski CM. Characterization of ecotin homologs from Campylobacter rectus and Campylobacter showae. PLoS One 2020; 15:e0244031. [PMID: 33378351 PMCID: PMC7773321 DOI: 10.1371/journal.pone.0244031] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 12/01/2020] [Indexed: 12/18/2022] Open
Abstract
Ecotin, first described in Escherichia coli, is a potent
inhibitor of a broad range of serine proteases including those typically
released by the innate immune system such as neutrophil elastase (NE). Here we
describe the identification of ecotin orthologs in various
Campylobacter species, including Campylobacter
rectus and Campylobacter showae residing in the
oral cavity and implicated in the development and progression of periodontal
disease in humans. To investigate the function of these ecotins in
vitro, the orthologs from C.
rectus and C. showae were
recombinantly expressed and purified from E.
coli. Using CmeA degradation/protection assays,
fluorescence resonance energy transfer and NE activity assays, we found that
ecotins from C. rectus and C.
showae inhibit NE, factor Xa and trypsin, but not the
Campylobacter jejuni serine protease HtrA or its ortholog
in E. coli, DegP. To further evaluate ecotin
function in vivo, an E. coli
ecotin-deficient mutant was complemented with the C.
rectus and C. showae
homologs. Using a neutrophil killing assay, we demonstrate that the low survival
rate of the E. coli ecotin-deficient mutant
can be rescued upon expression of ecotins from C.
rectus and C. showae. In
addition, the C. rectus and
C. showae ecotins partially compensate for
loss of N-glycosylation and increased protease susceptibility in the related
pathogen, Campylobacter jejuni, thus implicating a similar role
for these proteins in the native host to cope with the protease-rich environment
of the oral cavity.
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Affiliation(s)
- Cody Thomas
- Department of Microbiology and Complex Carbohydrate Research Center,
University of Georgia, Athens, Georgia, United States of
America
| | - Harald Nothaft
- Department of Biological Sciences, University of Alberta, Edmonton,
Alberta, Canada
| | - Ruchi Yadav
- Department of Infectious Diseases, University of Georgia, Athens,
Georgia, United States of America
| | - Christopher Fodor
- Department of Biological Sciences, University of Alberta, Edmonton,
Alberta, Canada
| | - Abofu Alemka
- Department of Biological Sciences, University of Alberta, Edmonton,
Alberta, Canada
| | - Oluwadamilola Oni
- Department of Infectious Diseases, University of Georgia, Athens,
Georgia, United States of America
| | - Michael Bell
- Department of Infectious Diseases, University of Georgia, Athens,
Georgia, United States of America
| | - Balázs Rada
- Department of Infectious Diseases, University of Georgia, Athens,
Georgia, United States of America
| | - Christine M. Szymanski
- Department of Microbiology and Complex Carbohydrate Research Center,
University of Georgia, Athens, Georgia, United States of
America
- Department of Biological Sciences, University of Alberta, Edmonton,
Alberta, Canada
- * E-mail:
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3
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Dubb RK, Nothaft H, Beadle B, Richards MR, Szymanski CM. N-glycosylation of the CmeABC multidrug efflux pump is needed for optimal function in Campylobacter jejuni. Glycobiology 2020; 30:105-119. [PMID: 31588498 DOI: 10.1093/glycob/cwz082] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 09/26/2019] [Accepted: 09/27/2019] [Indexed: 12/20/2022] Open
Abstract
Campylobacter jejuni is a prevalent gastrointestinal pathogen associated with increasing rates of antimicrobial resistance development. It was also the first bacterium demonstrated to possess a general N-linked protein glycosylation pathway capable of modifying > 80 different proteins, including the primary Campylobacter multidrug efflux pump, CmeABC. Here we demonstrate that N-glycosylation is necessary for the function of the efflux pump and may, in part, explain the evolutionary pressure to maintain this protein modification system. Mutants of cmeA in two common wildtype (WT) strains are highly susceptible to erythromycin (EM), ciprofloxacin and bile salts when compared to the isogenic parental strains. Complementation of the cmeA mutants with the native cmeA allele restores the WT phenotype, whereas expression of a cmeA allele with point mutations in both N-glycosylation sites is comparable to the cmeA mutants. Moreover, loss of CmeA glycosylation leads to reduced chicken colonization levels similar to the cmeA knock-out strain, while complementation fully restores colonization. Reconstitution of C. jejuni CmeABC into Escherichia coli together with the C. jejuni N-glycosylation pathway increases the EM minimum inhibitory concentration and decreases ethidium bromide accumulation when compared to cells lacking the pathway. Molecular dynamics simulations reveal that the protein structures of the glycosylated and non-glycosylated CmeA models do not vary from one another, and in vitro studies show no change in CmeA multimerization or peptidoglycan association. Therefore, we conclude that N-glycosylation has a broader influence on CmeABC function most likely playing a role in complex stability.
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Affiliation(s)
- Rajinder K Dubb
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Harald Nothaft
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Bernadette Beadle
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Michele R Richards
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Christine M Szymanski
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada.,Department of Microbiology and Complex Carbohydrate Research Center, University of Georgia, Athens, GA, USA
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4
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Duma J, Nothaft H, Weaver D, Fodor C, Beadle B, Linton D, Benoit SL, Scott NE, Maier RJ, Szymanski CM. Influence of Protein Glycosylation on Campylobacter fetus Physiology. Front Microbiol 2020; 11:1191. [PMID: 32625174 PMCID: PMC7313396 DOI: 10.3389/fmicb.2020.01191] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 05/11/2020] [Indexed: 01/01/2023] Open
Abstract
Campylobacter fetus is commonly associated with venereal disease and abortions in cattle and sheep, and can also cause intestinal or systemic infections in humans that are immunocompromised, elderly, or exposed to infected livestock. It is also believed that C. fetus infection can result from the consumption or handling of contaminated food products, but C. fetus is rarely detected in food since isolation methods are not suited for its detection and the physiology of the organism makes culturing difficult. In the related species, Campylobacter jejuni, the ability to colonize the host has been linked to N-linked protein glycosylation with quantitative proteomics demonstrating that glycosylation is interconnected with cell physiology. Using label-free quantitative (LFQ) proteomics, we found more than 100 proteins significantly altered in expression in two C. fetus subsp. fetus protein glycosylation (pgl) mutants (pglX and pglJ) compared to the wild-type. Significant increases in the expression of the (NiFe)-hydrogenase HynABC, catalyzing H2-oxidation for energy harvesting, correlated with significantly increased levels of cellular nickel, improved growth in H2 and increased hydrogenase activity, suggesting that N-glycosylation in C. fetus is involved in regulating the HynABC hydrogenase and nickel homeostasis. To further elucidate the function of the C. fetus pgl pathway and its enzymes, heterologous expression in Escherichia coli followed by mutational and functional analyses revealed that PglX and PglY are novel glycosyltransferases involved in extending the C. fetus hexasaccharide beyond the conserved core, while PglJ and PglA have similar activities to their homologs in C. jejuni. In addition, the pgl mutants displayed decreased motility and ethidium bromide efflux and showed an increased sensitivity to antibiotics. This work not only provides insight into the unique protein N-glycosylation pathway of C. fetus, but also expands our knowledge on the influence of protein N-glycosylation on Campylobacter cell physiology.
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Affiliation(s)
- Justin Duma
- Department of Microbiology, University of Georgia, Athens, GA, United States.,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
| | - Harald Nothaft
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Danielle Weaver
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Christopher Fodor
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Bernadette Beadle
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
| | - Dennis Linton
- School of Biological Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Stéphane L Benoit
- Department of Microbiology, University of Georgia, Athens, GA, United States
| | - Nichollas E Scott
- Department of Microbiology and Immunology, The Peter Doherty Institute, The University of Melbourne, Melbourne, VIC, Australia
| | - Robert J Maier
- Department of Microbiology, University of Georgia, Athens, GA, United States
| | - Christine M Szymanski
- Department of Microbiology, University of Georgia, Athens, GA, United States.,Complex Carbohydrate Research Center, University of Georgia, Athens, GA, United States
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5
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Barre Y, Nothaft H, Thomas C, Liu X, Li J, Ng KKS, Szymanski CM. A conserved DGGK motif is essential for the function of the PglB oligosaccharyltransferase from Campylobacter jejuni. Glycobiology 2017; 27:978-989. [DOI: 10.1093/glycob/cwx067] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2016] [Accepted: 07/20/2017] [Indexed: 11/14/2022] Open
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6
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Nothaft H, Davis B, Lock YY, Perez-Munoz ME, Vinogradov E, Walter J, Coros C, Szymanski CM. Engineering the Campylobacter jejuni N-glycan to create an effective chicken vaccine. Sci Rep 2016; 6:26511. [PMID: 27221144 PMCID: PMC4879521 DOI: 10.1038/srep26511] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/04/2016] [Indexed: 12/31/2022] Open
Abstract
Campylobacter jejuni is a predominant cause of human gastroenteritis worldwide. Source-attribution studies indicate that chickens are the main reservoir for infection, thus elimination of C. jejuni from poultry would significantly reduce the burden of human disease. We constructed glycoconjugate vaccines combining the conserved C. jejuni N-glycan with a protein carrier, GlycoTag, or fused to the Escherichia coli lipopolysaccharide-core. Vaccination of chickens with the protein-based or E. coli-displayed glycoconjugate showed up to 10-log reduction in C. jejuni colonization and induced N-glycan-specific IgY responses. Moreover, the live E. coli vaccine was cleared prior to C. jejuni challenge and no selection for resistant campylobacter variants was observed. Analyses of the chicken gut communities revealed that the live vaccine did not alter the composition or complexity of the microbiome, thus representing an effective and low-cost strategy to reduce C. jejuni in chickens and its subsequent entry into the food chain.
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Affiliation(s)
- Harald Nothaft
- Department of Biological Sciences, University of Alberta, Edmonton, Canada.,Alberta Glycomics Centre, University of Alberta, Edmonton, Canada
| | | | | | - Maria Elisa Perez-Munoz
- Department of Agricultural, Food &Nutritional Science, University of Alberta, Edmonton, Canada
| | - Evgeny Vinogradov
- Human Health Therapeutics, National Research Council, Ottawa, Canada
| | - Jens Walter
- Department of Biological Sciences, University of Alberta, Edmonton, Canada.,Department of Agricultural, Food &Nutritional Science, University of Alberta, Edmonton, Canada
| | | | - Christine M Szymanski
- Department of Biological Sciences, University of Alberta, Edmonton, Canada.,Alberta Glycomics Centre, University of Alberta, Edmonton, Canada
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7
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Dwivedi R, Nothaft H, Reiz B, Whittal RM, Szymanski CM. Generation of free oligosaccharides from bacterial protein N-linked glycosylation systems. Biopolymers 2016; 99:772-83. [PMID: 23749285 DOI: 10.1002/bip.22296] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2013] [Accepted: 05/28/2013] [Indexed: 11/10/2022]
Abstract
All Campylobacter species are capable of N-glycosylating their proteins and releasing the same oligosaccharides into the periplasm as free oligosaccharides (fOS). Previously, analysis of fOS production in Campylobacter required fOS derivatization or large culture volumes and several chromatography steps prior to fOS analysis. In this study, label-free fOS extraction and purification methods were developed and coupled with quantitative analysis techniques. Our method follows three simple steps: (1) fOS extraction from the periplasmic space, (2) fOS purification using silica gel chromatography followed by porous graphitized carbon purification and (3) fOS analysis and accurate quantitation using a combination of thin-layer chromatography, mass spectrometry, NMR, and high performance anion exchange chromatography with pulsed amperometric detection. We applied our techniques to analyze fOS from C. jejuni, C. lari, C. rectus, and C. fetus fetus that produce different fOS structures. We accurately quantified fOS in Campylobacter species that ranged from 7.80 (±0.84) to 49.82 (±0.46) nmoles per gram of wet cell pellet and determined that the C. jejuni fOS comprises 2.5% of the dry cell weight. In addition, a novel di-phosphorylated fOS species was identified in C. lari. This method provides a sensitive and quantitative method to investigate the genesis, biology and breakdown of fOS in the bacterial N-glycosylation systems.
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Affiliation(s)
- Ritika Dwivedi
- Alberta Glycomics Center and Department of Biological Sciences, University of Alberta, Canada
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8
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Abstract
There is an ongoing race between bacterial evolution and medical advances. Pathogens have the advantages of short generation times and horizontal gene transfer that enable rapid adaptation to new host environments and therapeutics that currently outpaces clinical research. Antibiotic resistance, the growing impact of nosocomial infections, cancer-causing bacteria, the risk of zoonosis, and the possibility of biowarfare all emphasize the increasingly urgent need for medical research focussed on bacterial pathogens. Bacterial glycoproteins are promising targets for alternative therapeutic intervention since they are often surface exposed, involved in host-pathogen interactions, required for virulence, and contain distinctive glycan structures. The potential exists to exploit these unique structures to improve clinical prevention, diagnosis, and treatment strategies. Translation of the potential in this field to actual clinical impact is an exciting prospect for fighting infectious diseases.
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Affiliation(s)
- Kelly M Fulton
- a Human Health Therapeutics Portfolio , National Research Council Canada , Ottawa , Canada
| | - Jeffrey C Smith
- b Department of Chemistry and Institute of Biochemistry , Carleton University , Ottawa , Canada
| | - Susan M Twine
- a Human Health Therapeutics Portfolio , National Research Council Canada , Ottawa , Canada
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9
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Morello E, Mallet A, Konto-Ghiorghi Y, Chaze T, Mistou MY, Oliva G, Oliveira L, Di Guilmi AM, Trieu-Cuot P, Dramsi S. Evidence for the Sialylation of PilA, the PI-2a Pilus-Associated Adhesin of Streptococcus agalactiae Strain NEM316. PLoS One 2015; 10:e0138103. [PMID: 26407005 PMCID: PMC4583379 DOI: 10.1371/journal.pone.0138103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2015] [Accepted: 08/25/2015] [Indexed: 01/20/2023] Open
Abstract
Streptococcus agalactiae (or Group B Streptococcus, GBS) is a commensal bacterium present in the intestinal and urinary tracts of approximately 30% of humans. We and others previously showed that the PI-2a pilus polymers, made of the backbone pilin PilB, the tip adhesin PilA and the cell wall anchor protein PilC, promote adhesion to host epithelia and biofilm formation. Affinity-purified PI-2a pili from GBS strain NEM316 were recognized by N-acetylneuraminic acid (NeuNAc, also known as sialic acid) specific lectins such as Elderberry Bark Lectin (EBL) suggesting that pili are sialylated. Glycan profiling with twenty different lectins combined with monosaccharide composition by HPLC suggested that affinity-purified PI-2a pili are modified by N-glycosylation and decorated with sialic acid attached to terminal galactose. Analysis of various relevant mutants in the PI-2a pilus operon by flow-cytometry and electron microscopy analyses pointed to PilA as the pilus subunit modified by glycosylation. Double labeling using PilB antibody and EBL lectin, which specifically recognizes N-acetylneuraminic acid attached to galactose in α-2, 6, revealed a characteristic binding of EBL at the tip of the pilus structures, highly reminiscent of PilA localization. Expression of a secreted form of PilA using an inducible promoter showed that this recombinant PilA binds specifically to EBL lectin when produced in the native GBS context. In silico search for potentially glycosylated asparagine residues in PilA sequence pointed to N427 and N597, which appear conserved and exposed in the close homolog RrgA from S. pneumoniae, as likely candidates. Conversion of these two asparagyl residues to glutamyl resulted in a higher instability of PilA. Our results provide the first evidence that the tip PilA adhesin can be glycosylated, and suggest that this modification is critical for PilA stability and may potentially influence interactions with the host.
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Affiliation(s)
- Eric Morello
- Institut Pasteur, Unité des Bactéries Pathogènes à Gram positif, Paris, France
- Centre National de la Recherche Scientifique (CNRS ERL 3526), Paris, France
| | - Adeline Mallet
- Institut Pasteur, Imagopole, Ultrastructural Microscopy Platform, Paris, France
| | - Yoan Konto-Ghiorghi
- Institut Pasteur, Unité des Bactéries Pathogènes à Gram positif, Paris, France
- Centre National de la Recherche Scientifique (CNRS ERL 3526), Paris, France
| | - Thibault Chaze
- Institut Pasteur, Spectrométrie de Masse Structurale et Protéomique, Paris, France
- INRA UMR 1319, MICALIS, Jouy-en-Josas, France
| | | | - Giulia Oliva
- Institut Pasteur, Unité des Bactéries Pathogènes à Gram positif, Paris, France
- Centre National de la Recherche Scientifique (CNRS ERL 3526), Paris, France
| | - Liliana Oliveira
- Institut Pasteur, Unité des Bactéries Pathogènes à Gram positif, Paris, France
- Centre National de la Recherche Scientifique (CNRS ERL 3526), Paris, France
| | - Anne-Marie Di Guilmi
- Université Grenoble Alpes, Institut de Biologie Structurale (IBS), Grenoble, France
| | - Patrick Trieu-Cuot
- Institut Pasteur, Unité des Bactéries Pathogènes à Gram positif, Paris, France
- Centre National de la Recherche Scientifique (CNRS ERL 3526), Paris, France
| | - Shaynoor Dramsi
- Institut Pasteur, Unité des Bactéries Pathogènes à Gram positif, Paris, France
- Centre National de la Recherche Scientifique (CNRS ERL 3526), Paris, France
- * E-mail:
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10
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Garcia-Quintanilla F, Iwashkiw JA, Price NL, Stratilo C, Feldman MF. Production of a recombinant vaccine candidate against Burkholderia pseudomallei exploiting the bacterial N-glycosylation machinery. Front Microbiol 2014; 5:381. [PMID: 25120536 PMCID: PMC4114197 DOI: 10.3389/fmicb.2014.00381] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 07/08/2014] [Indexed: 11/13/2022] Open
Abstract
Vaccines developing immune responses toward surface carbohydrates conjugated to proteins are effective in preventing infection and death by bacterial pathogens. Traditional production of these vaccines utilizes complex synthetic chemistry to acquire and conjugate the glycan to a protein. However, glycoproteins produced by bacterial protein glycosylation systems are significantly easier to produce, and could possible be used as vaccine candidates. In this work, we functionally expressed the Burkholderia pseudomallei O polysaccharide (OPS II), the Campylobacter jejuni oligosaccharyltransferase (OTase), and a suitable glycoprotein (AcrA) in a designer E. coli strain with a higher efficiency for production of glycoconjugates. We were able to produce and purify the OPS II-AcrA glycoconjugate, and MS analysis confirmed correct glycan was produced and attached. We observed the attachment of the O-acetylated deoxyhexose directly to the acceptor protein, which expands the range of substrates utilized by the OTase PglB. Injection of the glycoprotein into mice generated an IgG immune response against B. pseudomallei, and this response was partially protective against an intranasal challenge. Our experiments show that bacterial engineered glycoconjugates can be utilized as vaccine candidates against B. pseudomallei. Additionally, our new E. coli strain SDB1 is more efficient in glycoprotein production, and could have additional applications in the future.
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Affiliation(s)
| | - Jeremy A. Iwashkiw
- Department of Biological Sciences, University of AlbertaEdmonton, AB, Canada
| | - Nancy L. Price
- Department of Biological Sciences, University of AlbertaEdmonton, AB, Canada
| | - Chad Stratilo
- Defence Research and Development Canada – Suffield Research CentreMedicine Hat, AB, Canada
| | - Mario F. Feldman
- Department of Biological Sciences, University of AlbertaEdmonton, AB, Canada
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11
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Gao B, Lara-Tejero M, Lefebre M, Goodman AL, Galán JE. Novel components of the flagellar system in epsilonproteobacteria. mBio 2014; 5:e01349-14. [PMID: 24961693 PMCID: PMC4073491 DOI: 10.1128/mbio.01349-14] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Accepted: 06/02/2014] [Indexed: 12/13/2022] Open
Abstract
UNLABELLED Motility is essential for the pathogenesis of many bacterial species. Most bacteria move using flagella, which are multiprotein filaments that rotate propelled by a cell wall-anchored motor using chemical energy. Although some components of the flagellar apparatus are common to many bacterial species, recent studies have shown significant differences in the flagellar structures of different bacterial species. The molecular bases for these differences, however, are not understood. The flagella from epsilonproteobacteria, which include the bacterial pathogens Campylobacter jejuni and Helicobacter pylori, are among the most divergent. Using next-generation sequencing combined with transposon mutagenesis, we have conducted a comprehensive high-throughput genetic screen in Campylobacter jejuni, which identified several novel components of its flagellar system. Biochemical analyses detected interactions between the identified proteins and known components of the flagellar machinery, and in vivo imaging located them to the bacterial poles, where flagella assemble. Most of the identified new components are conserved within but restricted to epsilonproteobacteria. These studies provide insight into the divergent flagella of this group of bacteria and highlight the complexity of this remarkable structure, which has adapted to carry out its conserved functions in the context of widely diverse bacterial species. IMPORTANCE Motility is essential for the normal physiology and pathogenesis of many bacterial species. Most bacteria move using flagella, which are multiprotein filaments that rotate propelled by a motor that uses chemical energy as fuel. Although some components of the flagellar apparatus are common to many bacterial species, recent studies have shown significant divergence in the flagellar structures across bacterial species. However, the molecular bases for these differences are not understood. The flagella from epsilonproteobacteria, which include the bacterial pathogens Campylobacter jejuni and Helicobacter pylori, are among the most divergent. We conducted a comprehensive genetic screen in Campylobacter jejuni and identified several novel components of the flagellar system. These studies provide important information to understand how flagella have adapted to function in the context of widely diverse sets of bacterial species and bring unique insight into the evolution and function of this remarkable bacterial organelle.
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Affiliation(s)
- Beile Gao
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Maria Lara-Tejero
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Matthew Lefebre
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | - Jorge E Galán
- Department of Microbial Pathogenesis, Yale University School of Medicine, New Haven, Connecticut, USA
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12
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Jarrell KF, Ding Y, Meyer BH, Albers SV, Kaminski L, Eichler J. N-linked glycosylation in Archaea: a structural, functional, and genetic analysis. Microbiol Mol Biol Rev 2014; 78:304-41. [PMID: 24847024 PMCID: PMC4054257 DOI: 10.1128/mmbr.00052-13] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
N-glycosylation of proteins is one of the most prevalent posttranslational modifications in nature. Accordingly, a pathway with shared commonalities is found in all three domains of life. While excellent model systems have been developed for studying N-glycosylation in both Eukarya and Bacteria, an understanding of this process in Archaea was hampered until recently by a lack of effective molecular tools. However, within the last decade, impressive advances in the study of the archaeal version of this important pathway have been made for halophiles, methanogens, and thermoacidophiles, combining glycan structural information obtained by mass spectrometry with bioinformatic, genetic, biochemical, and enzymatic data. These studies reveal both features shared with the eukaryal and bacterial domains and novel archaeon-specific aspects. Unique features of N-glycosylation in Archaea include the presence of unusual dolichol lipid carriers, the use of a variety of linking sugars that connect the glycan to proteins, the presence of novel sugars as glycan constituents, the presence of two very different N-linked glycans attached to the same protein, and the ability to vary the N-glycan composition under different growth conditions. These advances are the focus of this review, with an emphasis on N-glycosylation pathways in Haloferax, Methanococcus, and Sulfolobus.
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Affiliation(s)
- Ken F Jarrell
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Yan Ding
- Department of Biomedical and Molecular Sciences, Queen's University, Kingston, Ontario, Canada
| | - Benjamin H Meyer
- Molecular Biology of Archaea, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Sonja-Verena Albers
- Molecular Biology of Archaea, Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Lina Kaminski
- Department of Life Sciences, Ben Gurion University, Beersheva, Israel
| | - Jerry Eichler
- Department of Life Sciences, Ben Gurion University, Beersheva, Israel
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13
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Brödel AK, Sonnabend A, Roberts LO, Stech M, Wüstenhagen DA, Kubick S. IRES-mediated translation of membrane proteins and glycoproteins in eukaryotic cell-free systems. PLoS One 2013; 8:e82234. [PMID: 24376523 PMCID: PMC3869664 DOI: 10.1371/journal.pone.0082234] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 10/22/2013] [Indexed: 02/04/2023] Open
Abstract
Internal ribosome entry site (IRES) elements found in the 5′ untranslated region of mRNAs enable translation initiation in a cap-independent manner, thereby representing an alternative to cap-dependent translation in cell-free protein expression systems. However, IRES function is largely species-dependent so their utility in cell-free systems from different species is rather limited. A promising approach to overcome these limitations would be the use of IRESs that are able to recruit components of the translation initiation apparatus from diverse origins. Here, we present a solution to this technical problem and describe the ability of a number of viral IRESs to direct efficient protein expression in different eukaryotic cell-free expression systems. The IRES from the intergenic region (IGR) of the Cricket paralysis virus (CrPV) genome was shown to function efficiently in four different cell-free systems based on lysates derived from cultured Sf21, CHO and K562 cells as well as wheat germ. Our results suggest that the CrPV IGR IRES-based expression vector is universally applicable for a broad range of eukaryotic cell lysates. Sf21, CHO and K562 cell-free expression systems are particularly promising platforms for the production of glycoproteins and membrane proteins since they contain endogenous microsomes that facilitate the incorporation of membrane-spanning proteins and the formation of post-translational modifications. We demonstrate the use of the CrPV IGR IRES-based expression vector for the enhanced synthesis of various target proteins including the glycoprotein erythropoietin and the membrane proteins heparin-binding EGF-like growth factor receptor as well as epidermal growth factor receptor in the above mentioned eukaryotic cell-free systems. CrPV IGR IRES-mediated translation will facilitate the development of novel eukaryotic cell-free expression platforms as well as the high-yield synthesis of desired proteins in already established systems.
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Affiliation(s)
- Andreas K. Brödel
- Fraunhofer Institute for Biomedical Engineering (IBMT) Branch Potsdam-Golm, Potsdam, Germany
| | - Andrei Sonnabend
- Fraunhofer Institute for Biomedical Engineering (IBMT) Branch Potsdam-Golm, Potsdam, Germany
| | - Lisa O. Roberts
- Faculty of Health and Medical Sciences, University of Surrey, Guildford, United Kingdom
| | - Marlitt Stech
- Fraunhofer Institute for Biomedical Engineering (IBMT) Branch Potsdam-Golm, Potsdam, Germany
| | - Doreen A. Wüstenhagen
- Fraunhofer Institute for Biomedical Engineering (IBMT) Branch Potsdam-Golm, Potsdam, Germany
| | - Stefan Kubick
- Fraunhofer Institute for Biomedical Engineering (IBMT) Branch Potsdam-Golm, Potsdam, Germany
- * E-mail:
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14
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Identification of genes involved in the biosynthesis of the third and fourth sugars of the Methanococcus maripaludis archaellin N-linked tetrasaccharide. J Bacteriol 2013; 195:4094-104. [PMID: 23836872 DOI: 10.1128/jb.00668-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
N-glycosylation is a protein posttranslational modification found in all three domains of life. Many surface proteins in Archaea, including S-layer proteins, pilins, and archaellins (archaeal flagellins) are known to contain N-linked glycans. In Methanococcus maripaludis, the archaellins are modified at multiple sites with an N-linked tetrasaccharide with the structure Sug-1,4-β-ManNAc3NAmA6Thr-1,4-β-GlcNAc3NAcA-1,3-β-GalNAc, where Sug is the unique sugar (5S)-2-acetamido-2,4-dideoxy-5-O-methyl-α-l-erythro-hexos-5-ulo-1,5-pyranose. In this study, four genes--mmp1084, mmp1085, mmp1086, and mmp1087--were targeted to determine their potential involvement of the biosynthesis of the sugar components in the N-glycan, based on bioinformatics analysis and proximity to a number of genes which have been previously demonstrated to be involved in the N-glycosylation pathway. The genes mmp1084 to mmp1087 were shown to be cotranscribed, and in-frame deletions of each gene as well as a Δmmp1086Δmmp1087 double mutant were successfully generated. All mutants were archaellated and motile. Mass spectrometry examination of purified archaella revealed that in Δmmp1084 mutant cells, the threonine linked to the third sugar of the glycan was missing, indicating a putative threonine transferase function of MMP1084. Similar analysis of the archaella of the Δmmp1085 mutant cells demonstrated that the glycan lacked the methyl group at the C-5 position of the terminal sugar, indicating that MMP1085 is a methyltransferase involved in the biosynthesis of this unique sugar. Deletion of the remaining two genes, mmp1086 and mmp1087, either singularly or together, had no effect on the structure of the archaellin N-glycan. Because of their demonstrated involvement in the N-glycosylation pathway, we designated mmp1084 as aglU and mmp1085 as aglV.
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15
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Nyirenda J, Matsumoto S, Saitoh T, Maita N, Noda NN, Inagaki F, Kohda D. Crystallographic and NMR evidence for flexibility in oligosaccharyltransferases and its catalytic significance. Structure 2012. [PMID: 23177926 DOI: 10.1016/j.str.2012.10.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Oligosaccharyltransferase (OST) is a membrane-bound enzyme that catalyzes the transfer of an oligosaccharide to an asparagine residue in glycoproteins. It possesses a binding pocket that recognizes Ser and Thr residues at the +2 position in the N-glycosylation consensus, Asn-X-Ser/Thr. We determined the crystal structures of the C-terminal globular domains of the catalytic subunits of two archaeal OSTs. A comparison with previously determined structures identified a segment with remarkable conformational plasticity, induced by crystal contact effects. We characterized its dynamic properties in solution by (15)N NMR relaxation analyses. Intriguingly, the mobile region contains the +2 Ser/Thr-binding pocket. In agreement, the flexibility restriction forced by an engineered disulfide crosslink abolished the enzymatic activity, and its cleavage fully restored activity. These results suggest the necessity of multiple conformational states in the reaction. The dynamic nature of the Ser/Thr pocket could facilitate the efficient scanning of N-glycosylation sequons along nascent polypeptide chains.
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Affiliation(s)
- James Nyirenda
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Shunsuke Matsumoto
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Takashi Saitoh
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan
| | - Nobuo Maita
- Institute of Enzyme Research, Tokushima University, Tokushima 770-8503, Japan
| | - Nobuo N Noda
- Department of Structural Biology, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Fuyuhiko Inagaki
- Department of Structural Biology, Faculty of Advanced Life Science, Hokkaido University, Sapporo 001-0021, Japan
| | - Daisuke Kohda
- Division of Structural Biology, Medical Institute of Bioregulation, Kyushu University, Fukuoka 812-8582, Japan; Research Center for Advanced Immunology, Kyushu University, Fukuoka 812-8582, Japan.
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16
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Nothaft H, Scott NE, Vinogradov E, Liu X, Hu R, Beadle B, Fodor C, Miller WG, Li J, Cordwell SJ, Szymanski CM. Diversity in the protein N-glycosylation pathways within the Campylobacter genus. Mol Cell Proteomics 2012; 11:1203-19. [PMID: 22859570 DOI: 10.1074/mcp.m112.021519] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The foodborne bacterial pathogen, Campylobacter jejuni, possesses an N-linked protein glycosylation (pgl) pathway involved in adding conserved heptasaccharides to asparagine-containing motifs of >60 proteins, and releasing the same glycan into its periplasm as free oligosaccharides. In this study, comparative genomics of all 30 fully sequenced Campylobacter taxa revealed conserved pgl gene clusters in all but one species. Structural, phylogenetic and immunological studies showed that the N-glycosylation systems can be divided into two major groups. Group I includes all thermotolerant taxa, capable of growth at the higher body temperatures of birds, and produce the C. jejuni-like glycans. Within group I, the niche-adapted C. lari subgroup contain the smallest genomes among the epsilonproteobacteria, and are unable to glucosylate their pgl pathway glycans potentially reminiscent of the glucosyltransferase regression observed in the O-glycosylation system of Neisseria species. The nonthermotolerant Campylobacters, which inhabit a variety of hosts and niches, comprise group II and produce an unexpected diversity of N-glycan structures varying in length and composition. This includes the human gut commensal, C. hominis, which produces at least four different N-glycan structures, akin to the surface carbohydrate diversity observed in the well-studied commensal, Bacteroides. Both group I and II glycans are immunogenic and cell surface exposed, making these structures attractive targets for vaccine design and diagnostics.
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Affiliation(s)
- Harald Nothaft
- Alberta Glycomics Centre and Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada
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17
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Identification of genes involved in the acetamidino group modification of the flagellin N-linked glycan of Methanococcus maripaludis. J Bacteriol 2012; 194:2693-702. [PMID: 22408155 DOI: 10.1128/jb.06686-11] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
N-linked glycosylation of protein is a posttranslational modification found in all three domains of life. The flagellin proteins of the archaeon Methanococcus maripaludis are known to be modified with an N-linked tetrasaccharide consisting of N-acetylgalactosamine (GalNAc), a diacetylated glucuronic acid (GlcNAc3NAc), an acetylated and acetamidino-modified mannuronic acid with a substituted threonine group (ManNAc3NAmA6Thr), and a novel terminal sugar residue [(5S)-2-acetamido-2,4-dideoxy-5-O-methyl-α-L-erythro-hexos-5-ulo-1,5-pyranose]. To identify genes involved in biosynthesis of the component sugars of this glycan, three genes, mmp1081, mmp1082, and mmp1083, were targeted for in-frame deletion, based on their annotation and proximity to glycosyltransferase genes known to be involved in assembly of the glycan. Mutants carrying a deletion in any of these three genes remained flagellated and motile. A strain with a deletion of mmp1081 had lower-molecular-mass flagellins in Western blots. Mass spectrometry of purified flagella revealed a truncated glycan with the terminal sugar absent and the threonine residue and the acetamidino group missing from the third sugar. No glycan modification was seen in either the Δmmp1082 or Δmmp1083 mutant grown in complex Balch III medium. However, a glycan identical to the Δmmp1081 glycan was observed when the Δmmp1082 or Δmmp1083 mutant was grown under ammonia-limited conditions. We hypothesize that MMP1082 generates ammonia and tunnels it through MMP1083 to MMP1081, which acts as the amidotransferase, modifying the third sugar residue of the M. maripaludis glycan with the acetamidino group.
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Gebhart C, Ielmini MV, Reiz B, Price NL, Aas FE, Koomey M, Feldman MF. Characterization of exogenous bacterial oligosaccharyltransferases in Escherichia coli reveals the potential for O-linked protein glycosylation in Vibrio cholerae and Burkholderia thailandensis. Glycobiology 2012; 22:962-74. [DOI: 10.1093/glycob/cws059] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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Affiliation(s)
- Ryan M Schmaltz
- The Department of Chemistry and Skaggs Institute for Chemical Biology, 10550 North Torrey Pines Road, La Jolla, California 92037, USA
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20
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Dube DH, Champasa K, Wang B. Chemical tools to discover and target bacterial glycoproteins. Chem Commun (Camb) 2011; 47:87-101. [DOI: 10.1039/c0cc01557a] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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22
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Biosynthesis and role of N-linked glycosylation in cell surface structures of archaea with a focus on flagella and s layers. Int J Microbiol 2010; 2010:470138. [PMID: 20976295 PMCID: PMC2952790 DOI: 10.1155/2010/470138] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2010] [Accepted: 08/01/2010] [Indexed: 11/17/2022] Open
Abstract
The genetics and biochemistry of the N-linked glycosylation system of Archaea have been investigated over the past 5 years using flagellins and S layers as reporter proteins in the model organisms, Methanococcus voltae, Methanococcus maripaludis, and Haloferax volcanii. Structures of archaeal N-linked glycans have indicated a variety of linking sugars as well as unique sugar components. In M. voltae, M. maripaludis, and H. volcanii, a number of archaeal glycosylation genes (agl) have been identified by deletion and complementation studies. These include many of the glycosyltransferases and the oligosaccharyltransferase needed to assemble the glycans as well as some of the genes encoding enzymes required for the biosynthesis of the sugars themselves. The N-linked glycosylation system is not essential for any of M. voltae, M. maripaludis, or H. volcanii, as demonstrated by the successful isolation of mutants carrying deletions in the oligosaccharyltransferase gene aglB (a homologue of the eukaryotic Stt3 subunit of the oligosaccharyltransferase complex). However, mutations that affect the glycan structure have serious effects on both flagellation and S layer function.
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