Undecaprenyl phosphate N,N'-diacetylbacillosamine 1-phosphate transferase

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Undecaprenyl phosphate N,N'-diacetylbacillosamine 1-phosphate transferase
Identifiers
EC no. 2.7.8.36
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Phosphoglycosyl transferase C (PglC) is an enzyme belonging to a class known as monotopic phosphoglycosyl transferases (PGT). PGTs are required for the synthesis of glycoconjugates on the membrane surface of bacteria. Glycoconjugates, such as glycoproteins, are imperative for bacterial communication as well as host cell interactions between prokaryotic and eukaryotic cells lending to bacteria's pathogenicity. [1] [2]

Contents

Phosphoglycosyl transferase C (from Campylobacter jejuni)
Identifiers
Organism Campylobacter jejuni
SymbolPglC
Entrez 905415
PDB 5W7L
RefSeq (Prot) WP_251831164.1
UniProt Q0P9D0
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Structures Swiss-model
Domains InterPro

Background

Depiction of the gram-negative cell wall consisting of an outer membrane of LPS, a middle layer of peptidoglycan, and an inner plasma membrane. New gram negative membrane.jpg
Depiction of the gram-negative cell wall consisting of an outer membrane of LPS, a middle layer of peptidoglycan, and an inner plasma membrane.

PglC is found in the pathogenic gram-negative organism Campylobacter jejuni (C. jejuni). Infection from C. jejuni results in acute gastroenteritis followed by vomiting, diarrhea, fever and abdominal pain. [3] The most common route of infection is through undercooked poultry as birds are a common source of C. jejuni. [4] Recent studies have also shown an association between prior C. jejuni infection and the neurological syndrome Guillan-Barré. [3] [5] [6] The glycoconjugates, lipopolysaccharides (LPS), found in the membrane of the bacteria resemble gangliosides found in the human nervous system leading to the generation of autoantibodies which cause deterioration of neurons. [5] [6] Gangliosides can be found on neuronal cells and are membrane proteins that aid in cell-cell recognition and communication.

PglC belongs to a superfamily of enzymes known as monotopic phosphoglycsoyl transferases (monoPGT). These membrane-associated proteins catalyze the transfer of a phosphosugar from a soluble nucleoside diphosphate-activated donor to a polyprenol phosphate (Pren-P) acceptor within the membrane. [7] The product is then diversified via action of glycosyl transferases, to build a lipid linked oligosaccharide that will be flipped to the periplasm and form a glycoconjugate. Mono PGTs are unique to prokaryotes and essential for the production of glycoconjugates which mediate cell-host interactions during bacterial infections and are thus important for bacterial survival and pathogenicity. [7] [8]

Glycoconjugates are integral structures on the surface of cell membranes composed of carbohydrates linked to other biomolecules such as proteins or lipids. These structures serve as a shield to the environment as well as aid in pathogenesis and viability of the bacterium itself. Glycoconjugates are also known to comprise adhesins used for host colonization and invasion. [1] [9] C. jejuni utilizes adhesins to attach to the epithelial cells of the gastrointestinal tract of humans allowing for colonization and infection of the human host. [10] [11] [9] Eukaryotic cells exhibit their own glycoconjugate ecosystem lending to immune system recognition of human cells as "self". Bacteria utilize glycan mimicry to pose as eukaryotic cells and evade immune response. [1] Several studies have shown that inactivated genes linked to glycan synthesis result in an inability of bacteria to adhere to host cells thereby inhibiting colonization of the host. [2] [12] [13] [14]

Structure of the protein PglC from Campylobacter concisus. Based on PyMol rendering of PDB 5W7L. PglC 5W7L.jpg
Structure of the protein PglC from Campylobacter concisus. Based on PyMol rendering of PDB 5W7L.

Structure

PglC is a membrane protein which only enters the first leaflet of the membrane on the cytosolic side of the lipid membrane interface. That is, the protein only sits in the first layer of the double-layered membrane. PglC from Campylobacter jejuni has yet to be structurally characterized, but an orthologue of PglC from Campylobacter concisus was elucidated in 2018 that represents the minimal functional core of this class of proteins. [8] Primary structure and hidden markov model computational analysis had actually predicted PglC to be a bitopic membrane protein. A bitopic membrane protein is one that passes through both layers of the membrane, but only does so once. However, structural characterization revealed that PglC only pans the first leaflet of the membrane. The structure also revealed significant characteristics of the protein important to its function such as the reentrant membrane helix (blue/light blue) that dips into the first leaflet of the membrane as well as the highly conserved Asp-Glu catalytic dyad within the active site (green loop). [8] The active site also holds a phosphate binding site and Mg2+ cofactor site important for coordinating reaction chemistry. [7] [8] The other helices exist at the membrane interface (red, green, orange).

Enzyme superfamily

Membrane proteins exist in three topologies: polytopic, bitopic, and monotopic, depending on the distribution of their domains throughout the membrane. [15] The domains of polytopic proteins cross the membrane multiple times while bitopic proteins may only pass through the membrane once typically with a transmembrane helix connecting two soluble domains outside of the membrane. [16] [17] Monotopic membranes make up the smallest percentage of membrane proteins (0.06%) and are embedded in a single layer of the membrane, not both. [15] While the topologies of bitopic and polytopic membrane proteins can be linked to their function, monotopic proteins' topologies have yet to inform any function of these unique proteins apart from commonly being found in pathways where several enzymes are localized in sequence within the membrane.

Depiction of how a monotopic membrane protein, PglC, differs in membrane topology compared to a polytopic protein, MraY. Monotopic vs polytopic.jpg
Depiction of how a monotopic membrane protein, PglC, differs in membrane topology compared to a polytopic protein, MraY.

PglC is the first structurally characterized member of the monotopic PGT superfamily. [15] [8] Other PGT superfamilies include the polytopic PGTs which are commonly exemplified by the proteins MraY and WecA. Although the three PGTs share the same function, they differ in structure and mechanism. PglC features a reentrant membrane helix that only spans the first leaflet of the membrane while MraY has multiple transmembrane helices. The mechanisms by which the two superfamilies' catalyze addition of an NDP-sugar (nucleoside di-phosphate) to a polyprenol acceptor within the membrane are unique. PglC utilizes a two-step ping pong mechanism that generates a covalent intermediate which is then available for nucleophilic attack by the polyprenol acceptor within the membrane. [7] MraY and other polytopic PGTs use a ternary complex mechanism whereby Pren-P and the NDP-sugar are reacted by enzyme within a single step. [18] [19] [7]

Function

PglC is involved in the first membrane-associated catalysis step involved in the synthesis of glycoconjugates in the bacterium Campylobacter jejuni. The substrate for PglC, UDP-di-N-acetyl-bacillosamine, is first synthesized in the cytosol by the enzymes PglD, PglE, and PglF. [20] PglC is responsible for linking the sugar, di-N-acetyl-bacillosamine, to the polyprenol phosphate (pren-p) acceptor within the membrane. PglC is also unique compared to its successors in the pathway due to the attachment of a phosphosugar to pren-p. PglA, PglJ, PglH, PglI, PglK, PglB are known as glycosyltransferases and each add their own respective sugars to the growing glycan, but there is no addition of a phosphoryl group. The phosphoryl group is integral for initiation of the membrane-associated part of the pathway, otherwise no successive sugars can be added to the growing glycan.

Mechanism

Mechanism of PglC.jpg

PglC catalyzes the generation of a polyprenol diphoshate-linked sugar (bacillosamine) via a ping pong mechanism. [7] The AspGlu catalytic dyad of PglC acts as a nucleophile to attack UDP-bacillosamine, releasing UMP in the process (step 1). A covalent intermediate characteristic of a ping pong mechanism is formed between the enzyme and the sugar via the phosphate group. Polyprenol phosphate (Pren-P), a membrane substrate, attacks the covalent intermediate, or phosphoglycosyl adduct, resulting in turnover of enzyme and attachment of the sugar to the Pren-P acceptor within the membrane. [7]

Related Research Articles

Peptidoglycan or murein is a unique large macromolecule, a polysaccharide, consisting of sugars and amino acids that forms a mesh-like layer (sacculus) that surrounds the bacterial cytoplasmic membrane. The sugar component consists of alternating residues of β-(1,4) linked N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM). Attached to the N-acetylmuramic acid is an oligopeptide chain made of three to five amino acids. The peptide chain can be cross-linked to the peptide chain of another strand forming the 3D mesh-like layer. Peptidoglycan serves a structural role in the bacterial cell wall, giving structural strength, as well as counteracting the osmotic pressure of the cytoplasm. This repetitive linking results in a dense peptidoglycan layer which is critical for maintaining cell form and withstanding high osmotic pressures, and it is regularly replaced by peptidoglycan production. Peptidoglycan hydrolysis and synthesis are two processes that must occur in order for cells to grow and multiply, a technique carried out in three stages: clipping of current material, insertion of new material, and re-crosslinking of existing material to new material.

<span class="mw-page-title-main">Glycoprotein</span> Protein with oligosaccharide modifications

Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. Secreted extracellular proteins are often glycosylated.

<span class="mw-page-title-main">Mannose</span> Chemical compound

Mannose is a sugar monomer of the aldohexose series of carbohydrates. It is a C-2 epimer of glucose. Mannose is important in human metabolism, especially in the glycosylation of certain proteins. Several congenital disorders of glycosylation are associated with mutations in enzymes involved in mannose metabolism.

Defined in the narrowest sense, glycobiology is the study of the structure, biosynthesis, and biology of saccharides that are widely distributed in nature. Sugars or saccharides are essential components of all living things and aspects of the various roles they play in biology are researched in various medical, biochemical and biotechnological fields.

<span class="mw-page-title-main">Lectin</span> Carbohydrate-binding protein

Lectins are carbohydrate-binding proteins that are highly specific for sugar groups that are part of other molecules, so cause agglutination of particular cells or precipitation of glycoconjugates and polysaccharides. Lectins have a role in recognition at the cellular and molecular level and play numerous roles in biological recognition phenomena involving cells, carbohydrates, and proteins. Lectins also mediate attachment and binding of bacteria, viruses, and fungi to their intended targets.

Glycosylation is the reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule in order to form a glycoconjugate. In biology, glycosylation usually refers to an enzyme-catalysed reaction, whereas glycation may refer to a non-enzymatic reaction.

<span class="mw-page-title-main">Sialic acid</span> Class of keto acid sugars

Sialic acids are a class of alpha-keto acid sugars with a nine-carbon backbone. The term "sialic acid" was first introduced by Swedish biochemist Gunnar Blix in 1952. The most common member of this group is N-acetylneuraminic acid found in animals and some prokaryotes.

<i>Campylobacter jejuni</i> Species of bacterium

Campylobacter jejuni is a species of pathogenic bacteria that is commonly associated with poultry, and is also often found in animal feces. This species of microbe is one of the most common causes of food poisoning in Europe and in the US, with the vast majority of cases occurring as isolated events rather than mass outbreaks. Active surveillance through the Foodborne Diseases Active Surveillance Network (FoodNet) indicates that about 20 cases are diagnosed each year for each 100,000 people in the US, while many more cases are undiagnosed or unreported; the CDC estimates a total of 1.5 million infections every year. The European Food Safety Authority reported 246,571 cases in 2018, and estimated approximately nine million cases of human campylobacteriosis per year in the European Union. Campylobacter jejuni infections are increasing at an alarming rate in Europe, North America, and Australia. In Africa, Asia, and the Middle East, data indicates that C. jejuni infections are endemic.

<span class="mw-page-title-main">Glycolipid</span> Class of chemical compounds

Glycolipids are lipids with a carbohydrate attached by a glycosidic (covalent) bond. Their role is to maintain the stability of the cell membrane and to facilitate cellular recognition, which is crucial to the immune response and in the connections that allow cells to connect to one another to form tissues. Glycolipids are found on the surface of all eukaryotic cell membranes, where they extend from the phospholipid bilayer into the extracellular environment.

The terms glycans and polysaccharides are defined by IUPAC as synonyms meaning "compounds consisting of a large number of monosaccharides linked glycosidically". However, in practice the term glycan may also be used to refer to the carbohydrate portion of a glycoconjugate, such as a glycoprotein, glycolipid, or a proteoglycan, even if the carbohydrate is only an oligosaccharide. Glycans usually consist solely of O-glycosidic linkages of monosaccharides. For example, cellulose is a glycan composed of β-1,4-linked D-glucose, and chitin is a glycan composed of β-1,4-linked N-acetyl-D-glucosamine. Glycans can be homo- or heteropolymers of monosaccharide residues, and can be linear or branched.

In molecular biology and biochemistry, glycoconjugates are the classification family for carbohydrates – referred to as glycans – which are covalently linked with chemical species such as proteins, peptides, lipids, and other compounds. Glycoconjugates are formed in processes termed glycosylation.

<span class="mw-page-title-main">Glycosyltransferase</span> Class of enzymes

Glycosyltransferases are enzymes that establish natural glycosidic linkages. They catalyze the transfer of saccharide moieties from an activated nucleotide sugar to a nucleophilic glycosyl acceptor molecule, the nucleophile of which can be oxygen- carbon-, nitrogen-, or sulfur-based.

<span class="mw-page-title-main">DPAGT1</span> Protein-coding gene in the species Homo sapiens

UDP-N-acetylglucosamine—dolichyl-phosphate N-acetylglucosaminephosphotransferase is an enzyme that in humans is encoded by the DPAGT1 gene.

O-linked glycosylation is the attachment of a sugar molecule to the oxygen atom of serine (Ser) or threonine (Thr) residues in a protein. O-glycosylation is a post-translational modification that occurs after the protein has been synthesised. In eukaryotes, it occurs in the endoplasmic reticulum, Golgi apparatus and occasionally in the cytoplasm; in prokaryotes, it occurs in the cytoplasm. Several different sugars can be added to the serine or threonine, and they affect the protein in different ways by changing protein stability and regulating protein activity. O-glycans, which are the sugars added to the serine or threonine, have numerous functions throughout the body, including trafficking of cells in the immune system, allowing recognition of foreign material, controlling cell metabolism and providing cartilage and tendon flexibility. Because of the many functions they have, changes in O-glycosylation are important in many diseases including cancer, diabetes and Alzheimer's. O-glycosylation occurs in all domains of life, including eukaryotes, archaea and a number of pathogenic bacteria including Burkholderia cenocepacia, Neisseria gonorrhoeae and Acinetobacter baumannii.

Campylobacter coli is a Gram-negative, microaerophilic, non-endospore-forming, S-shaped bacterial species within genus Campylobacter. In humans, C. coli can cause campylobacteriosis, a diarrhoeal disease which is the most frequently reported foodborne illness in the European Union. C. coli grows slowly with an optimum temperature of 42 °C. When exposed to air for long periods, they become spherical or coccoid shaped.

UDP-4-amino-4,6-dideoxy-N-acetyl-alpha-D-glucosamine N-acetyltransferase is an enzyme with systematic name acetyl-CoA:UDP-4-amino-4,6-dideoxy-N-acetyl-alpha-D-glucosamine N-acetyltransferase. This enzyme catalyses the following chemical reaction

N,N'-diacetylbacillosaminyl-diphospho-undecaprenol alpha-1,3-N-acetylgalactosaminyltransferase is an enzyme with systematic name UDP-N-acetyl-alpha-D-galactosamine:N,N'-diacetyl-alpha-D-bacillosaminyl-diphospho-tritrans,heptacis-undecaprenol 3-alpha-N-acetyl-D-galactosaminyltransferase. This enzyme catalyses the following chemical reaction

GalNAc-alpha-(1->4)-GalNAc-alpha-(1->3)-diNAcBac-PP-undecaprenol alpha-1,4-N-acetyl-D-galactosaminyltransferase is an enzyme with systematic name UDP-N-acetyl-alpha-D-galactosamine:GalNAc-alpha-(1->4)-GalNAc-alpha-(1->3)-diNAcBac-PP-tritrans,heptacis-undecaprenol 4-alpha-N-acetyl-D-galactosaminyltransferase. This enzyme catalyses the following chemical reaction

UDP-4-amino-4,6-dideoxy-N-acetyl-alpha-D-glucosamine transaminase is an enzyme with systematic name UDP-4-amino-4,6-dideoxy-N-acetyl-alpha-D-glucosamine:2-oxoglutarate aminotransferase. This enzyme catalyses the following chemical reaction

N-glycosyltransferase is an enzyme in prokaryotes which transfers individual hexoses onto asparagine sidechains in substrate proteins, using a nucleotide-bound intermediary, within the cytoplasm. They are distinct from regular N-glycosylating enzymes, which are oligosaccharyltransferases that transfer pre-assembled oligosaccharides. Both enzyme families however target a shared amino acid sequence asparagine—-any amino acid except proline—serine or threonine (N–x–S/T), with some variations.

References

  1. 1 2 3 Varki, Ajit; Gagneux, Pascal (2015), Varki, Ajit; Cummings, Richard D.; Esko, Jeffrey D.; Stanley, Pamela (eds.), "Biological Functions of Glycans", Essentials of Glycobiology (3rd ed.), Cold Spring Harbor (NY): Cold Spring Harbor Laboratory Press, doi:10.1101/glycobiology.3e.007 (inactive 31 January 2024), PMID   28876862 , retrieved 2022-11-14{{citation}}: CS1 maint: DOI inactive as of January 2024 (link)
  2. 1 2 Tra VN, Dube DH (May 2014). "Glycans in pathogenic bacteria--potential for targeted covalent therapeutics and imaging agents". Chemical Communications. 50 (36): 4659–4673. doi:10.1039/C4CC00660G. PMC   4049282 . PMID   24647371.
  3. 1 2 Perez-Perez, Guillermo I.; Blaser, Martin J. (1996), Baron, Samuel (ed.), "Campylobacter and Helicobacter", Medical Microbiology (4th ed.), Galveston (TX): University of Texas Medical Branch at Galveston, ISBN   978-0-9631172-1-2, PMID   21413331 , retrieved 2022-11-20
  4. ↑ Allos BM (April 2001). "Campylobacter jejuni Infections: update on emerging issues and trends". Clinical Infectious Diseases. 32 (8): 1201–1206. doi: 10.1086/319760 . PMID   11283810.
  5. 1 2 McCarthy N, Giesecke J (March 2001). "Incidence of Guillain-Barré syndrome following infection with Campylobacter jejuni". American Journal of Epidemiology. 153 (6): 610–614. doi: 10.1093/aje/153.6.610 . PMID   11257070.
  6. 1 2 Nachamkin I, Allos BM, Ho T (July 1998). "Campylobacter species and Guillain-Barré syndrome". Clinical Microbiology Reviews. 11 (3): 555–567. doi:10.1128/CMR.11.3.555. PMC   88896 . PMID   9665983.
  7. 1 2 3 4 5 6 7 Das D, Kuzmic P, Imperiali B (July 2017). "Analysis of a dual domain phosphoglycosyl transferase reveals a ping-pong mechanism with a covalent enzyme intermediate". Proceedings of the National Academy of Sciences of the United States of America. 114 (27): 7019–7024. doi: 10.1073/pnas.1703397114 . PMC   5502628 . PMID   28630348.
  8. 1 2 3 4 5 Ray LC, Das D, Entova S, Lukose V, Lynch AJ, Imperiali B, Allen KN (June 2018). "Membrane association of monotopic phosphoglycosyl transferase underpins function". Nature Chemical Biology. 14 (6): 538–541. doi:10.1038/s41589-018-0054-z. PMC   6202225 . PMID   29769739.
  9. 1 2 Rubinchik S, Seddon A, Karlyshev AV (March 2012). "Molecular mechanisms and biological role of Campylobacter jejuni attachment to host cells". European Journal of Microbiology & Immunology. 2 (1): 32–40. doi:10.1556/EuJMI.2.2012.1.6. PMC   3933988 . PMID   24611119.
  10. ↑ Fauchere JL, Rosenau A, Veron M, Moyen EN, Richard S, Pfister A (November 1986). "Association with HeLa cells of Campylobacter jejuni and Campylobacter coli isolated from human feces". Infection and Immunity. 54 (2): 283–287. doi:10.1128/iai.54.2.283-287.1986. PMC   260156 . PMID   3770943.
  11. ↑ Janssen R, Krogfelt KA, Cawthraw SA, van Pelt W, Wagenaar JA, Owen RJ (July 2008). "Host-pathogen interactions in Campylobacter infections: the host perspective". Clinical Microbiology Reviews. 21 (3): 505–518. doi:10.1128/CMR.00055-07. PMC   2493085 . PMID   18625685.
  12. ↑ Schirm M, Soo EC, Aubry AJ, Austin J, Thibault P, Logan SM (June 2003). "Structural, genetic and functional characterization of the flagellin glycosylation process in Helicobacter pylori". Molecular Microbiology. 48 (6): 1579–1592. doi: 10.1046/j.1365-2958.2003.03527.x . PMID   12791140. S2CID   24095927.
  13. ↑ Smedley JG, Jewell E, Roguskie J, Horzempa J, Syboldt A, Stolz DB, Castric P (December 2005). "Influence of pilin glycosylation on Pseudomonas aeruginosa 1244 pilus function". Infection and Immunity. 73 (12): 7922–7931. doi:10.1128/iai.73.12.7922-7931.2005. PMC   1307089 . PMID   16299283.
  14. ↑ Alemka A, Nothaft H, Zheng J, Szymanski CM (May 2013). "N-glycosylation of Campylobacter jejuni surface proteins promotes bacterial fitness". Infection and Immunity. 81 (5): 1674–1682. doi:10.1128/iai.01370-12. PMC   3648013 . PMID   23460522.
  15. 1 2 3 Allen KN, Entova S, Ray LC, Imperiali B (January 2019). "Monotopic Membrane Proteins Join the Fold". Trends in Biochemical Sciences. 44 (1): 7–20. doi:10.1016/j.tibs.2018.09.013. PMC   6309722 . PMID   30337134.
  16. ↑ Lord JM, High S (March 2005). "Polytopic proteins: preventing aggregation in the membrane". Current Biology. 15 (5): R169–R171. doi: 10.1016/j.cub.2005.02.043 . PMID   15753028. S2CID   14404516.
  17. ↑ Zviling M, Kochva U, Arkin IT (March 2007). "How important are transmembrane helices of bitopic membrane proteins?". Biochimica et Biophysica Acta (BBA) - Biomembranes. 1768 (3): 387–392. doi:10.1016/j.bbamem.2006.11.019. PMID   17258687.
  18. ↑ O'Toole KH, Bernstein HM, Allen KN, Imperiali B (June 2021). "The surprising structural and mechanistic dichotomy of membrane-associated phosphoglycosyl transferases". Biochemical Society Transactions. 49 (3): 1189–1203. doi:10.1042/BST20200762. PMC   9206117 . PMID   34100892.
  19. ↑ Al-Dabbagh B, Olatunji S, Crouvoisier M, El Ghachi M, Blanot D, Mengin-Lecreulx D, Bouhss A (August 2016). "Catalytic mechanism of MraY and WecA, two paralogues of the polyprenyl-phosphate N-acetylhexosamine 1-phosphate transferase superfamily". Biochimie. 127: 249–257. doi:10.1016/j.biochi.2016.06.005. PMID   27312048.
  20. ↑ Kumar M, Balaji PV (May 2011). "Comparative genomics analysis of completely sequenced microbial genomes reveals the ubiquity of N-linked glycosylation in prokaryotes". Molecular BioSystems. 7 (5): 1629–1645. doi:10.1039/c0mb00259c. PMID   21387023.
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