1
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Ghosh M, Narindoshvili T, Thoden JB, Schumann ME, Holden HM, Raushel FM. Biosynthesis of Cytidine Diphosphate-6-d-Glucitol for the Capsular Polysaccharides of Campylobacter jejuni. Biochemistry 2024; 63:699-710. [PMID: 38386885 PMCID: PMC10918830 DOI: 10.1021/acs.biochem.3c00706] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/12/2024] [Accepted: 02/02/2024] [Indexed: 02/24/2024]
Abstract
Campylobacter jejuni is a Gram-negative pathogenic bacterium commonly found in chickens and is the leading cause of human diarrheal disease worldwide. The various serotypes of C. jejuni produce structurally distinct capsular polysaccharides (CPSs) on the exterior surfaces of the cell wall. The capsular polysaccharide from C. jejuni serotype HS:5 is composed of a repeating sequence of d-glycero-d-manno-heptose and d-glucitol-6-phosphate. We previously defined the pathway for the production of d-glycero-d-manno-heptose in C. jejuni. Here, we elucidate the biosynthetic pathway for the assembly of cytidine diphosphate (CDP)-6-d-glucitol by the combined action of two previously uncharacterized enzymes. The first enzyme catalyzes the formation of CDP-6-d-fructose from cytidine triphosphate (CTP) and d-fructose-6-phosphate. The second enzyme reduces CDP-6-d-fructose with NADPH to generate CDP-6-d-glucitol. Using sequence similarity network (SSN) and genome neighborhood network (GNN) analyses, we predict that these pairs of proteins are responsible for the biosynthesis of CDP-6-d-glucitol and/or CDP-d-mannitol in the lipopolysaccharides (LPSs) and capsular polysaccharides in more than 200 other organisms. In addition, high resolution X-ray structures of the second enzyme are reported, which provide novel insight into the manner in which an open-chain nucleotide-linked sugar is harbored in an active site cleft.
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Affiliation(s)
- Manas
K. Ghosh
- Department
of Chemistry, Texas A&M University, College Station, Texas 77845, United States
| | - Tamari Narindoshvili
- Department
of Chemistry, Texas A&M University, College Station, Texas 77845, United States
| | - James B. Thoden
- Department
of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Mitchell E. Schumann
- Department
of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Hazel M. Holden
- Department
of Biochemistry, University of Wisconsin, Madison, Wisconsin 53706, United States
| | - Frank M. Raushel
- Department
of Chemistry, Texas A&M University, College Station, Texas 77845, United States
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2
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Cui L, Cui A, Li Q, Yang L, Liu H, Shao W, Feng Y. Molecular Evolution of an Aminotransferase Based on Substrate–Enzyme Binding Energy Analysis for Efficient Valienamine Synthesis. ACS Catal 2022. [DOI: 10.1021/acscatal.2c03784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Li Cui
- State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Anqi Cui
- State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Qitong Li
- State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Lezhou Yang
- State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Hao Liu
- State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Wenguang Shao
- State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
| | - Yan Feng
- State Key Laboratory of Microbial Metabolism, School of Life Science & Biotechnology, and Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai 200240, China
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3
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Srivastava J, Balaji PV. Clues to reaction specificity in
PLP
‐dependent fold type I aminotransferases of monosaccharide biosynthesis. Proteins 2022; 90:1247-1258. [DOI: 10.1002/prot.26305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 01/20/2022] [Indexed: 11/10/2022]
Affiliation(s)
- Jaya Srivastava
- Department of Biosciences and Bioengineering Indian Institute of Technology Bombay Mumbai India
| | - Petety V. Balaji
- Department of Biosciences and Bioengineering Indian Institute of Technology Bombay Mumbai India
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4
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Cain JA, Dale AL, Cordwell SJ. Exploiting pglB Oligosaccharyltransferase-Positive and -Negative Campylobacter jejuni and a Multiprotease Digestion Strategy to Identify Novel Sites Modified by N-Linked Protein Glycosylation. J Proteome Res 2021; 20:4995-5009. [PMID: 34677046 DOI: 10.1021/acs.jproteome.1c00482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Campylobacter jejuni is a bacterial pathogen encoding a unique N-linked glycosylation (pgl) system that mediates attachment of a heptasaccharide to N-sequon-containing membrane proteins by the PglB oligosaccharyltransferase (OST). Many targets of PglB are known, yet only a fraction of sequons are experimentally confirmed, and site occupancy remains elusive. We exploited pglB-positive (wild-type; WT) and -negative (ΔpglB) proteomes to identify potential glycosites. The nonglycosylated forms of known glycopeptides were typically increased in protein normalized abundance in ΔpglB relative to WT and restored by pglB reintroduction (ΔpglB::pglB). Sequon-containing peptide abundances were thus consistent with significant site occupancy in the presence of the OST. Peptides with novel sequons were either unaltered (likely not glycosylated) or showed abundance consistent with known glycopeptides. Topology analysis revealed that unaltered sequons often displayed cytoplasmic localization, despite originating from membrane proteins. Novel glycosites were confirmed using parallel multiprotease digestion, LC-MS/MS, and FAIMS-MS to define the glycoproteomes of WT and ΔpglB::pglB C. jejuni. We identified 142 glycosites, of which 32 were novel, and 83% of sites predicted by proteomics were validated. There are now 166 experimentally verified C. jejuni glycosites and evidence for occupancy or nonoccupancy of 31 additional sites. This study serves as a model for the use of OST-negative cells and proteomics for highlighting novel glycosites and determining occupancy in a range of organisms.
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Affiliation(s)
- Joel A Cain
- Charles Perkins Centre, The University of Sydney, Sydney 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney 2006, Australia
| | - Ashleigh L Dale
- Charles Perkins Centre, The University of Sydney, Sydney 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney 2006, Australia
| | - Stuart J Cordwell
- Charles Perkins Centre, The University of Sydney, Sydney 2006, Australia.,School of Life and Environmental Sciences, The University of Sydney, Sydney 2006, Australia.,Sydney Mass Spectrometry, The University of Sydney, Sydney 2006, Australia
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5
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Seltzner CA, Ferek JD, Thoden JB, Holden HM. Characterization of an aminotransferase from Acanthamoeba polyphaga Mimivirus. Protein Sci 2021; 30:1882-1894. [PMID: 34076307 DOI: 10.1002/pro.4139] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 01/03/2023]
Abstract
Acanthamoeba polyphaga Mimivirus, a complex virus that infects amoeba, was first reported in 2003. It is now known that its DNA genome encodes for nearly 1,000 proteins including enzymes that are required for the biosynthesis of the unusual sugar 4-amino-4,6-dideoxy-d-glucose, also known as d-viosamine. As observed in some bacteria, the pathway for the production of this sugar initiates with a nucleotide-linked sugar, which in the Mimivirus is thought to be UDP-d-glucose. The enzyme required for the installment of the amino group at the C-4' position of the pyranosyl moiety is encoded in the Mimivirus by the L136 gene. Here, we describe a structural and functional analysis of this pyridoxal 5'-phosphate-dependent enzyme, referred to as L136. For this analysis, three high-resolution X-ray structures were determined: the wildtype enzyme/pyridoxamine 5'-phosphate/dTDP complex and the site-directed mutant variant K185A in the presence of either UDP-4-amino-4,6-dideoxy-d-glucose or dTDP-4-amino-4,6-dideoxy-d-glucose. Additionally, the kinetic parameters of the enzyme utilizing either UDP-d-glucose or dTDP-d-glucose were measured and demonstrated that L136 is efficient with both substrates. This is in sharp contrast to the structurally related DesI from Streptomyces venezuelae, whose three-dimensional architecture was previously reported by this laboratory. As determined in this investigation, DesI shows a profound preference in its catalytic efficiency for the dTDP-linked sugar substrate. This difference can be explained in part by a hydrophobic patch in DesI that is missing in L136. Notably, the structure of L136 reported here represents the first three-dimensional model for a virally encoded PLP-dependent enzyme and thus provides new information on sugar aminotransferases in general.
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Affiliation(s)
- Chase A Seltzner
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Justin D Ferek
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
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6
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Cain JA, Dale AL, Sumer-Bayraktar Z, Solis N, Cordwell SJ. Identifying the targets and functions of N-linked protein glycosylation in Campylobacter jejuni. Mol Omics 2021; 16:287-304. [PMID: 32347268 DOI: 10.1039/d0mo00032a] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Campylobacter jejuni is a major cause of bacterial gastroenteritis in humans that is primarily associated with the consumption of inadequately prepared poultry products, since the organism is generally thought to be asymptomatic in avian species. Unlike many other microorganisms, C. jejuni is capable of performing extensive post-translational modification (PTM) of proteins by N- and O-linked glycosylation, both of which are required for optimal chicken colonization and human virulence. The biosynthesis and attachment of N-glycans to C. jejuni proteins is encoded by the pgl (protein glycosylation) locus, with the PglB oligosaccharyltransferase (OST) enabling en bloc transfer of a heptasaccharide N-glycan from a lipid carrier in the inner membrane to proteins exposed within the periplasm. Seventy-eight C. jejuni glycoproteins (represented by 134 sites of experimentally verified N-glycosylation) have now been identified, and include inner and outer membrane proteins, periplasmic proteins and lipoproteins, which are generally of poorly defined or unknown function. Despite our extensive knowledge of the targets of this apparently widespread process, we still do not fully understand the role N-glycosylation plays biologically, although several phenotypes, including wild-type stress resistance, biofilm formation, motility and chemotaxis have been related to a functional pgl system. Recent work has described enzymatic processes (nitrate reductase NapAB) and antibiotic efflux (CmeABC) as major targets requiring N-glycan attachment for optimal function, and experimental evidence also points to roles in cell binding via glycan-glycan interactions, protein complex formation and protein stability by conferring protection against host and bacterial proteolytic activity. Here we examine the biochemistry of the N-linked glycosylation system, define its currently known protein targets and discuss evidence for the structural and functional roles of this PTM in individual proteins and globally in C. jejuni pathogenesis.
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Affiliation(s)
- Joel A Cain
- School of Life and Environmental Sciences, The University of Sydney, 2006, Australia and Charles Perkins Centre, The University of Sydney, Level 4 East, The Hub Building (D17), 2006, Australia.
| | - Ashleigh L Dale
- School of Life and Environmental Sciences, The University of Sydney, 2006, Australia and Charles Perkins Centre, The University of Sydney, Level 4 East, The Hub Building (D17), 2006, Australia.
| | - Zeynep Sumer-Bayraktar
- School of Life and Environmental Sciences, The University of Sydney, 2006, Australia and Charles Perkins Centre, The University of Sydney, Level 4 East, The Hub Building (D17), 2006, Australia.
| | - Nestor Solis
- School of Life and Environmental Sciences, The University of Sydney, 2006, Australia
| | - Stuart J Cordwell
- School of Life and Environmental Sciences, The University of Sydney, 2006, Australia and Charles Perkins Centre, The University of Sydney, Level 4 East, The Hub Building (D17), 2006, Australia. and Discipline of Pathology, School of Medical Sciences, The University of Sydney, 2006, Australia and Sydney Mass Spectrometry, The University of Sydney, 2006, Australia
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7
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Linehan MP, Thoden JB, Holden HM. Characterization of two enzymes from Psychrobacter cryohalolentis that are required for the biosynthesis of an unusual diacetamido-d-sugar. J Biol Chem 2021; 296:100463. [PMID: 33639157 PMCID: PMC8040287 DOI: 10.1016/j.jbc.2021.100463] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2021] [Revised: 02/19/2021] [Accepted: 02/23/2021] [Indexed: 01/14/2023] Open
Abstract
Psychrobacter cryohalolentis strain K5T is a Gram-negative organism first isolated in 2006. It has a complex O-antigen that contains, in addition to l-rhamnose and d-galactose, two diacetamido- and a triacetamido-sugar. The biochemical pathways for the production of these unusual sugars are presently unknown. Utilizing the published genome sequence of the organism, we hypothesized that the genes 0612, 0638, and 0637 encode for a 4,6-dehydratase, an aminotransferase, and an N-acetyltransferase, respectively, which would be required for the biosynthesis of one of the diacetamido-sugars, 2,4-diacetamido-2,4,6-trideoxy-d-glucose, starting from UDP-N-acetylglucosamine. Here we present functional and structural data on the proteins encoded by the 0638 and 0637 genes. The kinetic properties of these enzymes were investigated by a discontinuous HPLC assay. An X-ray crystallographic structure of 0638, determined in its external aldimine form to 1.3 Å resolution, demonstrated the manner in which the UDP ligand is positioned into the active site. It is strikingly different from that previously observed for PglE from Campylobacter jejuni, which functions on the same substrate. Four X-ray crystallographic structures were also determined for 0637 in various complexed states at resolutions between 1.3 and 1.55 Å. Remarkably, a tetrahedral intermediate mimicking the presumed transition state was trapped in one of the complexes. The data presented herein confirm the hypothesized functions of these enzymes and provide new insight into an unusual sugar biosynthetic pathway in Gram-negative bacteria. We also describe an efficient method for acetyl-CoA synthesis that allowed us to overcome its prohibitive cost for this analysis.
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Affiliation(s)
- Michael P Linehan
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, USA.
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8
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Nothaft H, Szymanski CM. New discoveries in bacterial N-glycosylation to expand the synthetic biology toolbox. Curr Opin Chem Biol 2019; 53:16-24. [DOI: 10.1016/j.cbpa.2019.05.032] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 05/21/2019] [Accepted: 05/31/2019] [Indexed: 12/20/2022]
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9
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Kurilung A, Keeratipusana C, Suriyaphol P, Hampson DJ, Prapasarakul N. Genomic analysis of Leptospira interrogans serovar Paidjan and Dadas isolates from carrier dogs and comparative genomic analysis to detect genes under positive selection. BMC Genomics 2019; 20:168. [PMID: 30832578 PMCID: PMC6399948 DOI: 10.1186/s12864-019-5562-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Accepted: 02/25/2019] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND Leptospirosis is an emerging infectious disease worldwide that can cause high morbidity and mortality rates in humans and animals. The causative spirochetes have reservoirs in mammalian hosts, but there has been limited analysis of the genomes of isolates recovered from animals. The aims of this study were to characterize genomic features of two Leptospira interrogans strains recently isolated from asymptomatic dogs in Thailand (strains CUDO5 and CDUO8), and to perform comparative genome analyses with other strains. Molecular adaptive evolution in L. interrogans as signaled by positive selection also was analyzed. RESULTS Whole genome sequence analysis revealed that strains CUDO5 and CUDO8 had genome sizes of approximately 4.9 Mbp with 35.1% GC contents. Using monoclonal antibodies, strains CUDO5 and CUDO8 were identified as serovars Paidjan and Dadas, respectively. These strains harbored genes known to be associated with acute and chronic infections. Using Single Nucleotide Polymorphisms phylogeny (SNPs) with 97 L. interrogans strains, CUDO5 and CUDO8 had closest genetic relatedness with each other. Nevertheless, the serovar determinant region (rfb locus) showed variations in the genes encoding sugar biosynthesis. Amongst 13 representative L. interrogans strains examined for molecular adaptive evolution through positive selection under the site-model of Phylogenetic Analysis of Maximum Likelihood, genes responsible for iron acquisition (tlyA and hbpA), motility (fliN2, flgK, and flhB) and thermal adaptation (lpxD1) were under increased selective pressure. CONCLUSIONS L. interrogans serovar Paidjan strain CUDO5 and serovar Dadas strain CUDO8 had close genetic relatedness as analyzed by SNPs phylogeny. They contained genes with established roles in acute and chronic leptospirosis. The rfb locus in both serovars showed gene variation associated with sugar biosynthesis. Positive selection analysis indicated that genes encoding factors involved in motility, temperature adaptation, and iron acquisition were under strong positive selection in L. interrogans. These may be associated with adaptation in the early stages of infection.
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Affiliation(s)
- Alongkorn Kurilung
- Department of Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand
| | - Chantisa Keeratipusana
- Bioinformatics and Data Management for Research Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Prapat Suriyaphol
- Bioinformatics and Data Management for Research Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - David J Hampson
- Department of Infectious Diseases and Public Health, College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Kowloon Tong, Hong Kong SAR
| | - Nuvee Prapasarakul
- Department of Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand. .,Diagnosis and Monitoring of Animal Pathogens Research Unit, Department of Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand.
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10
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Kaundinya CR, Savithri HS, Rao KK, Balaji PV. EpsN from Bacillus subtilis 168 has UDP-2,6-dideoxy 2-acetamido 4-keto glucose aminotransferase activity in vitro. Glycobiology 2019; 28:802-812. [PMID: 29982582 DOI: 10.1093/glycob/cwy063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 07/04/2018] [Indexed: 01/08/2023] Open
Abstract
The gene epsN of Bacillus subtilis 168 was cloned and overexpressed in Escherichia coli. Purified recombinant EpsN is shown to be a pyridoxal 5'-phosphate (PLP)-dependent aminotransferase by absorption spectroscopy, l-cycloserine inhibition and reverse phase HPLC studies. EpsN catalyzes the conversion of UDP-2,6-dideoxy 2-acetamido 4-keto glucose to UDP-2,6-dideoxy 2-acetamido 4-amino glucose. Lys190 was found by sequence comparison and site-directed mutagenesis to form Schiff base with PLP. Mutagenesis studies showed that, in addition to Lys190, Ser185, Glu164, Gly58 and Thr59 are essential for aminotransferase activity.
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Affiliation(s)
- Chinmayi R Kaundinya
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Handanahal S Savithri
- Department of Biochemistry, Indian Institute of Science, CV Raman Road, Bengaluru, India
| | - K Krishnamurthy Rao
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
| | - Petety V Balaji
- Department of Biosciences and Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, India
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11
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Riegert AS, Thoden JB, Schoenhofen IC, Watson DC, Young NM, Tipton PA, Holden HM. Structural and Biochemical Investigation of PglF from Campylobacter jejuni Reveals a New Mechanism for a Member of the Short Chain Dehydrogenase/Reductase Superfamily. Biochemistry 2017; 56:6030-6040. [PMID: 29053280 DOI: 10.1021/acs.biochem.7b00910] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Within recent years it has become apparent that protein glycosylation is not limited to eukaryotes. Indeed, in Campylobacter jejuni, a Gram-negative bacterium, more than 60 of its proteins are known to be glycosylated. One of the sugars found in such glycosylated proteins is 2,4-diacetamido-2,4,6-trideoxy-α-d-glucopyranose, hereafter referred to as QuiNAc4NAc. The pathway for its biosynthesis, initiating with UDP-GlcNAc, requires three enzymes referred to as PglF, PglE, and PlgD. The focus of this investigation is on PglF, an NAD+-dependent sugar 4,6-dehydratase known to belong to the short chain dehydrogenase/reductase (SDR) superfamily. Specifically, PglF catalyzes the first step in the pathway, namely, the dehydration of UDP-GlcNAc to UDP-2-acetamido-2,6-dideoxy-α-d-xylo-hexos-4-ulose. Most members of the SDR superfamily contain a characteristic signature sequence of YXXXK where the conserved tyrosine functions as a catalytic acid or a base. Strikingly, in PglF, this residue is a methionine. Here we describe a detailed structural and functional investigation of PglF from C. jejuni. For this investigation five X-ray structures were determined to resolutions of 2.0 Å or better. In addition, kinetic analyses of the wild-type and site-directed variants were performed. On the basis of the data reported herein, a new catalytic mechanism for a SDR superfamily member is proposed that does not require the typically conserved tyrosine residue.
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Affiliation(s)
- Alexander S Riegert
- Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States
| | - Ian C Schoenhofen
- National Research Council Canada, Human Health Therapeutics , Ottawa, Ontario K1A 0R6, Canada
| | - David C Watson
- National Research Council Canada, Human Health Therapeutics , Ottawa, Ontario K1A 0R6, Canada
| | - N Martin Young
- National Research Council Canada, Human Health Therapeutics , Ottawa, Ontario K1A 0R6, Canada
| | - Peter A Tipton
- Department of Biochemistry, University of Missouri , Columbia, Missouri 65211, United States
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin , Madison, Wisconsin 53706, United States
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12
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Dow GT, Gilbert M, Thoden JB, Holden HM. Structural investigation on WlaRG from Campylobacter jejuni: A sugar aminotransferase. Protein Sci 2017; 26:586-599. [PMID: 28028852 DOI: 10.1002/pro.3109] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 12/22/2016] [Indexed: 12/12/2022]
Abstract
Campylobacter jejuni is a Gram-negative bacterium that represents a leading cause of human gastroenteritis worldwide. Of particular concern is the link between C. jejuni infections and the subsequent development of Guillain-Barré syndrome, an acquired autoimmune disorder leading to paralysis. All Gram-negative bacteria contain complex glycoconjugates anchored to their outer membranes, but in most strains of C. jejuni, this lipoglycan lacks the O-antigen repeating units. Recent mass spectrometry analyses indicate that the C. jejuni 81116 (Penner serotype HS:6) lipoglycan contains two dideoxyhexosamine residues, and enzymological assay data show that this bacterial strain can synthesize both dTDP-3-acetamido-3,6-dideoxy-d-glucose and dTDP-3-acetamido-3,6-dideoxy-d-galactose. The focus of this investigation is on WlaRG from C. jejuni, which plays a key role in the production of these unusual sugars by functioning as a pyridoxal 5'-phosphate dependent aminotransferase. Here, we describe the first three-dimensional structures of the enzyme in various complexes determined to resolutions of 1.7 Å or higher. Of particular significance are the external aldimine structures of WlaRG solved in the presence of either dTDP-3-amino-3,6-dideoxy-d-galactose or dTDP-3-amino-3,6-dideoxy-d-glucose. These models highlight the manner in which WlaRG can accommodate sugars with differing stereochemistries about their C-4' carbon positions. In addition, we present a corrected structure of WbpE, a related sugar aminotransferase from Pseudomonas aeruginosa, solved to 1.3 Å resolution.
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Affiliation(s)
- Garrett T Dow
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Michel Gilbert
- National Research Council Canada, Human Health Therapeutics, Ottawa, Ontario, K1A 0R6, Canada
| | - James B Thoden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
| | - Hazel M Holden
- Department of Biochemistry, University of Wisconsin, Madison, Wisconsin, 53706
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13
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Xu Y, Zheng H, Zhang Y, Wang Y, Zhang J, Li Z, Cui S, Xin X, Ye Q, Chang YF, Wang J. Genomic Analysis of a New Serovar of Leptospira weilii Serogroup Manhao. Front Microbiol 2017; 8:149. [PMID: 28210253 PMCID: PMC5288384 DOI: 10.3389/fmicb.2017.00149] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 01/20/2017] [Indexed: 12/29/2022] Open
Abstract
Leptospirosis, caused by pathogenic Leptospira spp., is recognized as an important emerging zoonotic disease throughout the world. In this study, multiple approaches were used to characterize the recently discovered serovar Heyan strain L231. This strain can infect guinea pigs and belonged to the pathogenic species L. weilii. Genome sequencing analysis revealed the draft genome of 4.2 M bp with a G+C content of 40.67% for strain L231, and a total of 4,794 ORFs were identified. The strain L231 genome was found to have a larger LPS biosynthesis locus than that of strains L. interrogans serovar Lai and L. borgpetersenii serovar Hardjobovis. Phylogenomic reconstructions showed that the evolutionary position of L. weilii serovar Heyan was different from that of other serovars from serogroup Manhao. These findings may lead us to a better understanding of Leptospira pathogenesis and evolution.
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Affiliation(s)
- Yinghua Xu
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control Beijing, China
| | - Huajun Zheng
- Key Laboratory of Reproduction Regulation of NPFPC, Shanghai Institute of Planned Parenthood Research, IRD, Fudan UniversityShanghai, China; Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Zhangjiang Hi-Tech ParkShanghai, China
| | - Ying Zhang
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control Beijing, China
| | - Yuezhu Wang
- Shanghai-MOST Key Laboratory of Health and Disease Genomics, Chinese National Human Genome Center at Shanghai, Zhangjiang Hi-Tech Park Shanghai, China
| | - Jinlong Zhang
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control Beijing, China
| | - Zhe Li
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control Beijing, China
| | - Shenghui Cui
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control Beijing, China
| | - Xiaofang Xin
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control Beijing, China
| | - Qiang Ye
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control Beijing, China
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, Cornell University, Ithaca NY, USA
| | - Junzhi Wang
- Key Laboratory of the Ministry of Health for Research on Quality and Standardization of Biotech Products, National Institutes for Food and Drug Control Beijing, China
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Sugar and Spice Make Bacteria Not Nice: Protein Glycosylation and Its Influence in Pathogenesis. J Mol Biol 2016; 428:3206-3220. [DOI: 10.1016/j.jmb.2016.04.013] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 04/04/2016] [Accepted: 04/08/2016] [Indexed: 01/08/2023]
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