Show legend Show as text

Structure type: oligomer
Trivial name: lipid IV A, lipid IV(A)
Compound class: lipid A, glycolipid
Contained glycoepitopes: IEDB_135394,IEDB_135515,IEDB_141807,IEDB_151531

• Article ID: 496
  Trent MS "Biosynthesis, transport, and modification of lipid A" - Biochemistry and Cell Biology 82(1) (2004) 71-86
  

  Lipopolysaccharide (LPS) is the major surface molecule of Gram-negative bacteria and consists of three distinct structural domains: O-antigen, core, and lipid A. The lipid A (endotoxin) domain of LPS is a unique, glucosamine-based phospholipid that serves as the hydrophobic anchor of LPS and is the bioactive component of the molecule that is associated with Gram-negative septic shock. The structural genes encoding the enzymes required for the biosynthesis of Escherchia coli lipid A have been identified and characterized. Lipid A is often viewed as a constitutively synthesized structural molecule. However, determination of the exact chemical structures of lipid A from diverse Gram-negative bacteria shows that the molecule can be further modified in response to environmental stimuli. These modifications have been implicated in virulence of pathogenic Gram-negative bacteria and represent one of the molecular mechanisms of microbial surface remodeling used by bacteria to help evade the innate immune response. The intent of this review is to discuss the enzymatic machinery involved in the biosynthesis of lipid A, transport of the molecule, and finally, those enzymes involved in the modification of its structure in response to environmental stimuli.

  lipopolysaccharides, lipide A, endotoxine, membrane externe, MsbA

  NCBI PubMed ID: 15052329
  Journal NLM ID: 8606068
  Publisher: Ottawa: National Research Council of Canada
  Correspondence: trentms@mailetsu.edu
  Institutions: Department of Microbiology, Box 70579, East Tennessee State University, J.H. Quillen College of Medicine, Johnson City, TN 37614, U.S.A.
  
   
  
  Escherichia coli K-12, Salmonella typhimurium
  CSDB ID 9214 (all data & tools)
• Article ID: 564
  Sweet CR, Williams AH, Karbarz MJ, Werts C, Kalb SR, Cotter RJ, Raetz CR "Enzymatic synthesis of lipid A molecules with four amide-linked acyl chains. LpxA acyltransferases selective for an analog of UDP-N-acetylglucosamine in which an amine replaces the 3'-hydroxyl group" - Journal of Biological Chemistry 279(24) (2004) 25411-25419
  

  LpxA of Escherichia coli catalyzes the acylation of the glucosamine 3-OH group of UDP-GlcNAc, using R-3-hydroxymyristoyl-acyl carrier protein (ACP) as the donor substrate. We now demonstrate that LpxA in cell extracts of Mesorhizobium loti and Leptospira interrogans, which synthesize lipid A molecules containing 2,3-diamino-2,3-dideoxy-d-glucopyranose (GlcN3N) units in place of glucosamine, do not acylate UDP-GlcNAc. Instead, these LpxA acyltransferases require a UDP-Glc-NAc derivative (designated UDP 2-acetamido-3-amino-2,3-dideoxy-α-D-glucopyranose or UDP-GlcNAc3N), characterized in the preceding paper, in which an amine replaces the glucosamine 3-OH group. L. interrogans LpxA furthermore displays absolute selectivity for 3-hydroxylauroyl-ACP as the donor, whereas M. loti LpxA functions almost equally well with 10-, 12-, and 14-carbon 3-hydroxyacyl-ACPs. The substrate selectivity of L. interrogans LpxA is consistent with the structure of L. interrogans lipid A. The mechanism of L. interrogans LpxA appears to be similar to that of E. coli LpxA, given that the essential His(125) residue of E. coli LpxA is conserved and is also required for acyltransferase activity in L. interrogans. Acidithiobacillus ferrooxidans (an organism that makes lipid A molecules containing both GlcN and GlcN3N) has an ortholog of LpxA that is selective for UDP-GlcNAc3N, but the enzyme also catalyzes the acylation of UDP-GlcNAc at a slow rate. E. coli LpxA acylates UDP-GlcNAc and UDP-GlcNAc3N at comparable rates in vitro. However, UDP-GlcNAc3N is not synthesized in vivo, because E. coli lacks gnnA and gnnB. When the latter are supplied together with A. ferrooxidans lpxA, E. coli incorporates a significant amount of GlcN3N into its lipid A.

  Escherichia coli, lipid A, Acidithiobacillus, Acidithiobacillus ferrooxidans, acylation, acyltransferase, enzymatic synthesis, Leptospira interrogans

  NCBI PubMed ID: 15044493
  Publication DOI: 10.1074/jbc.M400597200
  Journal NLM ID: 2985121R
  Publisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
  Correspondence: raetz@biochem.duke.edu
  Institutions: Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA, Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, Paris, 75015, France, Middle Atlantic Mass Spectrometry Laboratory, Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
  Methods: PCR, DNA techniques, TLC, MALDI-TOF MS, genetic methods, biochemical methods, radioactivity measurement, mild alkaline hydrolysis
  
   
  
  Acidithiobacillus ferrooxidans ATCC 23270
  CSDB ID 31331 (all data & tools)
• Article ID: 1435
  Alexander C, Zähringer U "Chemical structure of lipid A - the primary immunomodulatory center of bacterial lipopolysaccharides" - Trends in Glycoscience and Glycotechnology 14(76) (2002) 69-86
  

  Lipopolysaccharides (LPS) are the major outer surface membrane components expressed by the vast majority of Gram-negative bacteria and have been identified to be extremely strong stimulators of innate or natural immunity in diverse eukaryotic species ranging from insects or plants to humans. Due to early observations on the induction of severe pathological forms of immunoactivation such as septic shock this class of bacterial surface molecules has been termed ‘endotoxins’. By combination of chemical analysis, mass spectrometry and NMR techniques, the chemical structures of LPS from a variety of Gram-negative bacteria have been characterized in detail. LPS consist of an extracellular poly- or oligosaccharide region that is anchored in the outer bacterial membrane by a specific glycolipid termed lipid A. The lipid A component has been identified to be the primary immunostimulatory center of LPS. An overview of major types of lipid A structures recently established is given, thus completing and updating previous reviews (1, 2). In the present review central structure-bioactivity-correlations are discussed with respect to immunoactivation of the mammalian phagocyte system. In addition to the classical group of strongly agonistic (highly endotoxic) forms of lipid A, several natural or synthetic lipid A structures have been identified that display comparatively low or even no phagocyte activation for a given mammalian species. Some members of the latter more heterogeneous group are capable to antagonize the effects of strongly stimulatory LPS/lipid A. LPS of Gram-negative bacteria have been found to express a certain degree of structural diversity with respect to three structural elements: the glycosyl part of lipid A (lipid A backbone), the number, charge and linkage of polar head-group substituents, and the number, position and chemical nature of various acyl residues directly or indirectly linked to the lipid A backbone. Among all these structural variations, the acylation pattern has been found to encode mostly for its strong agonistic or antagonistic immunostimulatory activities in various biosystems.

  Lipopolysaccharide, lipid A, variability, antagonists, immunomodulatory activity

  Publication DOI: 10.4052/tigg.14.69
  Journal NLM ID: 9425898
  Correspondence: uzaehr@fz-borstel.de
  Institutions: Research Center Borstel, Center of Medicine and Bio-Sciences Department of Immunochemistry and Biochemical Microbiology
  
   
  
  Escherichia coli
  CSDB ID 31310 (all data & tools)
• Article ID: 1489
  Tanamoto K "Dissociation of endotoxic activities in a chemically synthesized lipid A precursor after acetylation" - Infection and Immunity 63 (1995) 690-692
  

  In a previous study, a chemically synthesized disaccharide precursor of lipid A (406; identical to lipid IVA) was shown to have dramatically reduced lethality, B-cell mitogenicity, and tumor necrosis factor induction in macrophages when its hydroxyl groups were replaced with either succinyl or acetyl residues (K. Tanamoto, FEBS Lett. 351:325-329, 1994). Succinylated 406 was found to lose Limulus amoebocyte lysate gelation activity completely as a result of the modification (about 10(5)-fold), too, as expected. However, acetyl 406, surprisingly, exhibited activity comparable to that of the original 406. Both succinylated and acetylated 406 lost pyrogenicity completely. These results indicate that one of the typical endotoxic activities was dissociated from the others and that the ability to induce Limulus amoebocyte lysate gelation is not always representative of endotoxin activity.

  synthesis, lipid, lipid A, activity, precursor, acetylation, endotoxic, synthetic lipid A analog, succinylation

  NCBI PubMed ID: 7822041
  Journal NLM ID: 0246127
  Publisher: American Society for Microbiology
  Institutions: Division of Microbiology, National Institute of Health Sciences, Tokyo 158, Japan
  Methods: biological assays, pyrogenic test
  
   
  
  Escherichia coli
  CSDB ID 4996 (all data & tools)
• Article ID: 1492
  Zähringer U, Salvetzki R, Wagner F, Lindner B, Ulmer AJ "Structural and biological characterisation of a novel tetra-acyl lipid A from Escherichia coli F515 lipopolysaccharide acting as endotoxin antagonist in human monocytes" - Journal of Endotoxin Research 7(2) (2001) 133-146
  

  We here report on the structural analysis of a novel tetra-acyl lipid A (LA (tetra)) isolated from Escherichia coli deep rough (Re)-mutant strain F515. In addition to the biologically active hexa-acyl E. coli- type lipid A (compound 506), this incompletely acylated lipid A was found to be also present in the native LPS. Its structure was studied without further derivatisation by chemical analysis, matrix-assisted laser desorption/ionization mass spectrometry, and one- and two- dimensional (1)H- and (13)C-NMR spectroscopy. It was found to be structurally distinct from the tetra-acyl lipid A biosynthetic precursor Ia (compound 406) in lacking the primary (R)-3- hydroxytetradecanoic acid 14:0(3-OH) in position 3' ester-linked to the 'non-reducing' glucosamine (GlcN II). The hydroxyl group at the (R)-3- hydroxytetradecanoic acid attached to position 2' of GlcN II was found to be substituted by dodecanoic acid (12:0), thus forming a dodecanoyloxytetradecanoyl residue 14:0[3-O(12:0)]. The acylation pattern at the 'reducing' GlcN I was identical to that of compound 406 in having two primary (R)-3-hydroxy tetradecanoic acid residues [14:0(3- OH)] attached to positions 3 (ester-linked) and 2 (amide-linked), respectively. In human mononuclear cells (hMNC) the new LA (tetra) antagonized LPS-induced release of interleukin-1 (IL-1), interleukin-6 (IL-6), and tumor necrosis factor (TNF) in a dose-dependent manner with identical antagonistic potency as compared with compound 406. Also like compound 406, it was found to be an agonist in murine macrophage-like J774.1 cells.

  Lipopolysaccharide, Escherichia coli, lipid A, mass spectrometry, spectroscopy

  NCBI PubMed ID: 11521094
  Journal NLM ID: 9433350
  Publisher: Maney Publishing
  Correspondence: uzaehr@fz-borstel.de
  Institutions: Research Center Borstel, Center for Medicine and Biosciences, Borstel, Germany
  Methods: 13C NMR, 1H NMR, NMR-2D, TLC, 31P NMR, GLC, mild acid hydrolysis, MALDI-TOF MS, biological assays, composition analysis, NMR-1D, extraction
  
   
  
  Escherichia coli F515
  CSDB ID 5951 (all data & tools)
• Article ID: 1596
  Seydel U, Schromm AB, Brade L, Gronow S, Andra J, Müller M, Koch MH, Fukase K, Kataoka M, Hashimoto M, Kusumoto S, Brandenburg K "Physicochemical characterization of carboxymethyl lipid A derivatives in relation to biological activity" - FEBS Journal 272(2) (2005) 327-340
  

  Lipopolysaccharide (LPS) from the outer membrane of Gram-negative bacteria belongs to the most potent activators of the mammalian immune system. Its lipid moiety, lipid A, the 'endotoxic principle' of LPS, carries two negatively charged phosphate groups and six acyl chain residues in a defined asymmetric distribution (corresponding to synthetic compound 506). Tetraacyl lipid A (precursor IVa or synthetic 406), which lacks the two hydroxylated acyl chains, is agonistically completely inactive, but is a strong antagonist to bioactive LPS when administered to the cells before LPS addition. The two negative charges of lipid A, represented by the two phosphate groups, are essential for agonistic as well as for antagonistic activity and no highly active lipid A are known with negative charges other than phosphate groups. We hypothesized that the phosphate groups could be substituted by other negatively charged groups without changing the endotoxic properties of lipid A. To test this hypothesis, we synthesized carboxymethyl (CM) derivatives of hexaacyl lipid A (CM-506 and Bis-CM-506) and of tetraacyl lipid A (Bis-CM-406) and correlated their physicochemical with their endotoxic properties. We found that, similarly to compounds 506 and 406, also for their carboxymethyl derivatives a particular molecular ('endotoxic') conformation and with that, a particular aggregate structure is a prerequisite for high cytokine-inducing capacity and antagonistic activity, respectively. In other parameters such as acyl chain melting behaviour, antibody binding, activity in the Limulus lysate assay, and partially the binding of 3-deoxy-d-manno-oct-2-ulosonic acid transferase, strong deviations from the properties of the phosphorylated compounds were observed. These data allow a better understanding of endotoxic activity and its structural prerequisites.

  Lipopolysaccharide, inflammation, endotoxic shock, signal transduction

  NCBI PubMed ID: 15654872
  Publication DOI: 10.1111/j.1742-4658.2004.04471.x
  Journal NLM ID: 101229646
  Publisher: Blackwell Publishing
  Correspondence: useydel@fz-borstel.de
  Institutions: Forschungszentrum Borstel, Leibniz-Zentrum für Medizin und Biowissenschaften, D-23845 Borstel, Germany, Osaka University, Department of Chemistry, Osaka, Japan, European Molecular Biology Laboratory, c ⁄ o DESY, Hamburg, Germany
  Methods: chemical synthesis, biological assays, FTIR, serological methods
  
   
  
  Escherichia coli
  CSDB ID 31284 (all data & tools)
• Article ID: 3882
  Kusumoto S, Hashimoto M, Kawahara K "Structure and Synthesis of Lipid A" - Book: Lipid A in Cancer Therapy (series: Advances in Experimental Medicine and Biology) (2010) Vol. 667, 5-23
  

  Lipid A is the lipophilic partial structure of bacterial lipopolysaccharide (LPS), which is a characteristic and essential component of the cell surface architecture of Gram negative bacteria. LPS constitutes the outer leaflet of the lipid bilayer of outer membrane which covers the outermost surface of bacterial cells. Structurally, LPS is composed of covalently bound three distinct parts, i. e., O-antigenic polysaccharide, core oligosaccharide and glycolipid called lipid A (Fig. 1). Westphal and Luderitz found that the linkage between the core oligosaccharide and glycolipid is selectively cleaved by mild acid hydrolysis of LPS. They also observed that the liberated glycolipid, which they named lipid A, is responsible for the endotoxic activity of LPS. (1) Figure 1. Schematic structure of lipopolysaccharide (LPS).

  Lipopolysaccharide, synthesis, structure, O-antigenic polysaccharide, lipid A, glycolipid

  NCBI PubMed ID: 20665196
  Publisher: New York: Springer.
  Correspondence: skus@sunbor.or.jp
  Editors: Jeannin J-F
  Institutions: Suntory Institute for Bioorganic Research, Wakayamadai 1-1-1, Shimamoto-cho, Mishima-gun, Osaka, 618-8503, Japan
  
   
  
  Escherichia coli
  CSDB ID 31183 (all data & tools)
• Article ID: 5614
  Mohan S, Raetz CR "Endotoxin biosynthesis in Pseudomonas aeruginosa: enzymatic incorporation of laurate before 3-deoxy-D-manno-octulosonate" - Journal of Bacteriology 176(22) (1994) 6944-6951
  

  Unlike Escherichia coli, living cells of Pseudomonas aeruginosa can complete the fatty acylation of lipid A when the biosynthesis of 3-deoxy-D-manno-octulosonate (Kdo) is inhibited (R. C. Goldman, C. C. Doran, S. K. Kadam, and J. O. Capobianco, J. Biol. Chem. 263:5217-5233, 1988). In this study, we demonstrate the presence of a novel enzyme in extracts of P. aeruginosa that can transfer lauroyl-acyl carrier protein (ACP) to a tetraacyl disaccharide-1,4'-bis-phosphate precursor of lipid A (termed lipid IVA) that accumulates in Kdo-deficient mutants of E. coli. Comparable E. coli extracts cannot transfer laurate from lauroyl-ACP to lipid IVA, only to (Kdo)2-lipid IVA (K. A. Brozek, and C. R. H. Raetz, J. Biol. Chem. 265:15410-15417, 1990). P. aeruginosa extracts do not utilize myristoyl- or R-3-hydroxymyristoyl-ACP instead of lauroyl-ACP to acylate lipid IVA. Laurate incorporation in P. aeruginosa extracts is dependent upon time, protein concentration, and the presence of Triton X-100 but is inhibited by lauroyl-coenzyme A. P. aeruginosa extracts transfer only one laurate to lipid IVA, whereas E. coli extracts can transfer two laurates to (Kdo)2-lipid IVA. These results demonstrate that incorporation of laurate into lipid A does not require prior attachment of Kdo in all gram-negative bacteria

  Pseudomonas aeruginosa, Escherichia coli, endotoxin, glycolipid

  NCBI PubMed ID: 7961456
  Publication DOI: 10.1128/jb.176.22.6944-6951.1994
  Journal NLM ID: 2985120R
  Publisher: American Society for Microbiology
  Correspondence: raetz@biochem.duke.edu
  Institutions: Department of Biochemistry, Merck Research Laboratories, Rahway, USA
  Methods: FAB-MS, TLC, radiolabeling, radioactivity measurement, extraction, cell growth, centrifugation, HR-FAB-MS, protein determination
  
   
  
  Escherichia coli D21e7
  CSDB ID 47779 (all data & tools)
• Article ID: 6049
  Di Lorenzo F, Duda KA, Lanzetta R, Silipo A, De Castro C, Molinaro A "A Journey from Structure to Function of Bacterial Lipopolysaccharides" - Chemical Reviews (2021)
  

  Lipopolysaccharide (LPS) is a crucial constituent of the outer membrane of most Gram-negative bacteria, playing a fundamental role in the protection of bacteria from environmental stress factors, in drug resistance, in pathogenesis, and in symbiosis. During the last decades, LPS has been thoroughly dissected, and massive information on this fascinating biomolecule is now available. In this Review, we will give the reader a third millennium update of the current knowledge of LPS with key information on the inherent peculiar carbohydrate chemistry due to often puzzling sugar residues that are uniquely found on it. Then, we will drive the reader through the complex and multifarious immunological outcomes that any given LPS can raise, which is strictly dependent on its chemical structure. Further, we will argue about issues that still remain unresolved and that would represent the immediate future of LPS research. It is critical to address these points to complete our notions on LPS chemistry, functions, and roles, in turn leading to innovative ways to manipulate the processes involving such a still controversial and intriguing biomolecule.

  Lipopolysaccharide, LPS, structure, Pathogenesis, carbohydrate, function, gram negative bacteria

  NCBI PubMed ID: 34286971
  Publication DOI: 10.1021/acs.chemrev.0c01321
  Journal NLM ID: 2985134R
  Publisher: Chem Rev
  Correspondence: Antonio Molinaro
  Institutions: Department of Chemical Sciences, University of Naples Federico II, via Cinthia 4, 80126 Naples, Italy, Task Force on Microbiome Studies, University of Naples Federico II, Via Cinthia 4, 80126 Naples, Italy, Research Center Borstel Leibniz Lung Center, Parkallee 4a, 23845 Borstel, Germany, Department of Agricultural Sciences, University of Naples Federico II, Via Universita 96, 80055 Portici, Naples, Italy, Department of Chemistry, School of Science, Osaka University, 1-1 Osaka University Machikaneyama, Toyonaka, Osaka 560-0043, Japan
  
   
  
  Escherichia coli
  CSDB ID 7938 (all data & tools)
• Article ID: 6232
  Garcia-Vello P, Di Lorenzo F, Zucchetta D, Zamyatina A, De Castro C, Molinaro A "Lipopolysaccharide lipid A: A promising molecule for new immunity-based therapies and antibiotics" - Pharmacology and Therapeutics 230 (2022) 107970
  

  Lipopolysaccharides (LPS) are the main components of the external leaflet of the Gram-negative outer membrane and consist of three different moieties: lipid A, core oligosaccharide, and O-polysaccharide. The lipid A is a glucosamine disaccharide with different levels of acylation and phosphorylation, beside carrying, in certain cases, additional substituents on the sugar backbone. It is also the main immunostimulatory part of the LPS, as its recognition by the host immune system represents a fundamental event for detection of perilous microorganisms. Moreover, an uncontrolled immune response caused by a large amount of circulating LPS can lead to dramatic outcomes for human health, such as septic shock. The immunostimulant properties of an LPS incredibly vary depending on lipid A chemical structure, and for this reason, natural and synthetic variants of the lipid A are under study to develop new drugs that mimic or antagonise its natural effects. Here, we review past and recent findings on the lipid A as an antibiotic target and immune-therapeutic molecule, with a special attention on the crucial role of the chemical structure and its exploitation for conceiving novel strategies for treatment of several immune-related pathologies.

  Lipopolysaccharide, lipid A, inflammation, immune system, adjuvant

  NCBI PubMed ID: 34454000
  Publication DOI: 10.1016/j.pharmthera.2021.107970
  Journal NLM ID: 7905840
  Publisher: Oxford, Elmsford, NY: Pergamon Press
  Correspondence: P. Garcia-Vello ; A. Molinaro
  Institutions: Department of Chemical Sciences, University of Naples Federico II, Napoli, Italy, Department of Agricultural Sciences, University of Naples Federico II, Portici, Italy
  
   
  
  Yersinia pestis
  CSDB ID 20951 (all data & tools)

Show legend Show as text

Structure type: oligomer
Compound class: lipid A
Contained glycoepitopes: IEDB_141807,IEDB_151531

• Article ID: 564
  Sweet CR, Williams AH, Karbarz MJ, Werts C, Kalb SR, Cotter RJ, Raetz CR "Enzymatic synthesis of lipid A molecules with four amide-linked acyl chains. LpxA acyltransferases selective for an analog of UDP-N-acetylglucosamine in which an amine replaces the 3'-hydroxyl group" - Journal of Biological Chemistry 279(24) (2004) 25411-25419
  

  LpxA of Escherichia coli catalyzes the acylation of the glucosamine 3-OH group of UDP-GlcNAc, using R-3-hydroxymyristoyl-acyl carrier protein (ACP) as the donor substrate. We now demonstrate that LpxA in cell extracts of Mesorhizobium loti and Leptospira interrogans, which synthesize lipid A molecules containing 2,3-diamino-2,3-dideoxy-d-glucopyranose (GlcN3N) units in place of glucosamine, do not acylate UDP-GlcNAc. Instead, these LpxA acyltransferases require a UDP-Glc-NAc derivative (designated UDP 2-acetamido-3-amino-2,3-dideoxy-α-D-glucopyranose or UDP-GlcNAc3N), characterized in the preceding paper, in which an amine replaces the glucosamine 3-OH group. L. interrogans LpxA furthermore displays absolute selectivity for 3-hydroxylauroyl-ACP as the donor, whereas M. loti LpxA functions almost equally well with 10-, 12-, and 14-carbon 3-hydroxyacyl-ACPs. The substrate selectivity of L. interrogans LpxA is consistent with the structure of L. interrogans lipid A. The mechanism of L. interrogans LpxA appears to be similar to that of E. coli LpxA, given that the essential His(125) residue of E. coli LpxA is conserved and is also required for acyltransferase activity in L. interrogans. Acidithiobacillus ferrooxidans (an organism that makes lipid A molecules containing both GlcN and GlcN3N) has an ortholog of LpxA that is selective for UDP-GlcNAc3N, but the enzyme also catalyzes the acylation of UDP-GlcNAc at a slow rate. E. coli LpxA acylates UDP-GlcNAc and UDP-GlcNAc3N at comparable rates in vitro. However, UDP-GlcNAc3N is not synthesized in vivo, because E. coli lacks gnnA and gnnB. When the latter are supplied together with A. ferrooxidans lpxA, E. coli incorporates a significant amount of GlcN3N into its lipid A.

  Escherichia coli, lipid A, Acidithiobacillus, Acidithiobacillus ferrooxidans, acylation, acyltransferase, enzymatic synthesis, Leptospira interrogans

  NCBI PubMed ID: 15044493
  Publication DOI: 10.1074/jbc.M400597200
  Journal NLM ID: 2985121R
  Publisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
  Correspondence: raetz@biochem.duke.edu
  Institutions: Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA, Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, Paris, 75015, France, Middle Atlantic Mass Spectrometry Laboratory, Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
  Methods: PCR, DNA techniques, TLC, MALDI-TOF MS, genetic methods, biochemical methods, radioactivity measurement, mild alkaline hydrolysis
  
   
  
  Acidithiobacillus ferrooxidans ATCC 23270
  CSDB ID 31332 (all data & tools)

Show legend Show as text

Structure type: oligomer
Compound class: lipid A
Contained glycoepitopes: IEDB_141807,IEDB_151531

• Article ID: 564
  Sweet CR, Williams AH, Karbarz MJ, Werts C, Kalb SR, Cotter RJ, Raetz CR "Enzymatic synthesis of lipid A molecules with four amide-linked acyl chains. LpxA acyltransferases selective for an analog of UDP-N-acetylglucosamine in which an amine replaces the 3'-hydroxyl group" - Journal of Biological Chemistry 279(24) (2004) 25411-25419
  

  LpxA of Escherichia coli catalyzes the acylation of the glucosamine 3-OH group of UDP-GlcNAc, using R-3-hydroxymyristoyl-acyl carrier protein (ACP) as the donor substrate. We now demonstrate that LpxA in cell extracts of Mesorhizobium loti and Leptospira interrogans, which synthesize lipid A molecules containing 2,3-diamino-2,3-dideoxy-d-glucopyranose (GlcN3N) units in place of glucosamine, do not acylate UDP-GlcNAc. Instead, these LpxA acyltransferases require a UDP-Glc-NAc derivative (designated UDP 2-acetamido-3-amino-2,3-dideoxy-α-D-glucopyranose or UDP-GlcNAc3N), characterized in the preceding paper, in which an amine replaces the glucosamine 3-OH group. L. interrogans LpxA furthermore displays absolute selectivity for 3-hydroxylauroyl-ACP as the donor, whereas M. loti LpxA functions almost equally well with 10-, 12-, and 14-carbon 3-hydroxyacyl-ACPs. The substrate selectivity of L. interrogans LpxA is consistent with the structure of L. interrogans lipid A. The mechanism of L. interrogans LpxA appears to be similar to that of E. coli LpxA, given that the essential His(125) residue of E. coli LpxA is conserved and is also required for acyltransferase activity in L. interrogans. Acidithiobacillus ferrooxidans (an organism that makes lipid A molecules containing both GlcN and GlcN3N) has an ortholog of LpxA that is selective for UDP-GlcNAc3N, but the enzyme also catalyzes the acylation of UDP-GlcNAc at a slow rate. E. coli LpxA acylates UDP-GlcNAc and UDP-GlcNAc3N at comparable rates in vitro. However, UDP-GlcNAc3N is not synthesized in vivo, because E. coli lacks gnnA and gnnB. When the latter are supplied together with A. ferrooxidans lpxA, E. coli incorporates a significant amount of GlcN3N into its lipid A.

  Escherichia coli, lipid A, Acidithiobacillus, Acidithiobacillus ferrooxidans, acylation, acyltransferase, enzymatic synthesis, Leptospira interrogans

  NCBI PubMed ID: 15044493
  Publication DOI: 10.1074/jbc.M400597200
  Journal NLM ID: 2985121R
  Publisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
  Correspondence: raetz@biochem.duke.edu
  Institutions: Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA, Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, Paris, 75015, France, Middle Atlantic Mass Spectrometry Laboratory, Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
  Methods: PCR, DNA techniques, TLC, MALDI-TOF MS, genetic methods, biochemical methods, radioactivity measurement, mild alkaline hydrolysis
  
   
  
  Acidithiobacillus ferrooxidans ATCC 23270
  CSDB ID 31333 (all data & tools)

Show legend Show as text

Structure type: oligomer
Compound class: lipid A

• Article ID: 564
  Sweet CR, Williams AH, Karbarz MJ, Werts C, Kalb SR, Cotter RJ, Raetz CR "Enzymatic synthesis of lipid A molecules with four amide-linked acyl chains. LpxA acyltransferases selective for an analog of UDP-N-acetylglucosamine in which an amine replaces the 3'-hydroxyl group" - Journal of Biological Chemistry 279(24) (2004) 25411-25419
  

  LpxA of Escherichia coli catalyzes the acylation of the glucosamine 3-OH group of UDP-GlcNAc, using R-3-hydroxymyristoyl-acyl carrier protein (ACP) as the donor substrate. We now demonstrate that LpxA in cell extracts of Mesorhizobium loti and Leptospira interrogans, which synthesize lipid A molecules containing 2,3-diamino-2,3-dideoxy-d-glucopyranose (GlcN3N) units in place of glucosamine, do not acylate UDP-GlcNAc. Instead, these LpxA acyltransferases require a UDP-Glc-NAc derivative (designated UDP 2-acetamido-3-amino-2,3-dideoxy-α-D-glucopyranose or UDP-GlcNAc3N), characterized in the preceding paper, in which an amine replaces the glucosamine 3-OH group. L. interrogans LpxA furthermore displays absolute selectivity for 3-hydroxylauroyl-ACP as the donor, whereas M. loti LpxA functions almost equally well with 10-, 12-, and 14-carbon 3-hydroxyacyl-ACPs. The substrate selectivity of L. interrogans LpxA is consistent with the structure of L. interrogans lipid A. The mechanism of L. interrogans LpxA appears to be similar to that of E. coli LpxA, given that the essential His(125) residue of E. coli LpxA is conserved and is also required for acyltransferase activity in L. interrogans. Acidithiobacillus ferrooxidans (an organism that makes lipid A molecules containing both GlcN and GlcN3N) has an ortholog of LpxA that is selective for UDP-GlcNAc3N, but the enzyme also catalyzes the acylation of UDP-GlcNAc at a slow rate. E. coli LpxA acylates UDP-GlcNAc and UDP-GlcNAc3N at comparable rates in vitro. However, UDP-GlcNAc3N is not synthesized in vivo, because E. coli lacks gnnA and gnnB. When the latter are supplied together with A. ferrooxidans lpxA, E. coli incorporates a significant amount of GlcN3N into its lipid A.

  Escherichia coli, lipid A, Acidithiobacillus, Acidithiobacillus ferrooxidans, acylation, acyltransferase, enzymatic synthesis, Leptospira interrogans

  NCBI PubMed ID: 15044493
  Publication DOI: 10.1074/jbc.M400597200
  Journal NLM ID: 2985121R
  Publisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
  Correspondence: raetz@biochem.duke.edu
  Institutions: Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA, Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, Paris, 75015, France, Middle Atlantic Mass Spectrometry Laboratory, Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
  Methods: PCR, DNA techniques, TLC, MALDI-TOF MS, genetic methods, biochemical methods, radioactivity measurement, mild alkaline hydrolysis
  
   
  
  Acidithiobacillus ferrooxidans ATCC 23270, Leptospira interrogans
  CSDB ID 31334 (all data & tools)