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Structure type: oligomer
Compound class: CPS

• Article ID: 4365
  Ovchinnikova OG, Arbatsky NP, Chizhov AO, Kocharova NA, Shashkov AS, Rozalski A, Knirel YA "Structure of a polysaccharide from Providencia rustigianii O11 containing a novel amide of 2-acetamido-2-deoxygalacturonic acid with L-glutamyl-L-alanine" - Carbohydrate Research 349 (2012) 95-102
  

  An acidic polysaccharide was isolated from Providencia rustigianii O11 by the phenol-water extraction. The polysaccharide was cleaved by solvolysis with triflic acid to yield disaccharides with uronic acid derivatives at the non-reducing end. The polysaccharide and the disaccharides were studied by chemical analyses, high-resolution ESI MS, and 2D (1)H and (13)C NMR spectroscopy, and the following structure of the tetrasaccharide repeating unit of the polysaccharide was established: where GalNAcA stands for 2-acetamido-2-deoxygalacturonic acid, GalNAcA6GluAla for N-(2-acetamido-2-deoxygalacturonoyl)-l-glutam-1-yl-l-alanine, QuiNAc4NAcyl for 2-acetamido-4-[(S)-3-hydroxybutanoylamino]-2,4,6-trideoxyglucose (~75%) or 2,4-diacetamido-2,4,6-trideoxyglucose (~25%); the d configuration of GalNA and QuiN4N was ascribed tentatively. To the best of our knowledge, this is for the first time that an amide of uronic acid with a dipeptide is found in bacterial polysaccharides.

  Lipopolysaccharide, bacterial polysaccharide structure, Providencia rustigianii, 2-acetamido-2-deoxygalacturonamide, dipeptide

  NCBI PubMed ID: 22230711
  Publication DOI: 10.1016/j.carres.2011.12.012
  Journal NLM ID: 0043535
  Publisher: Elsevier
  Correspondence: olga.ovchinnikova@gmail.com
  Institutions: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia, Department of Immunobiology of Bacteria, Institute of Microbiology, Biotechnology and Immunology, University of Lodz, PL 90-237 Lodz, Poland
  Methods: 13C NMR, 1H NMR, GLC-MS, NMR-2D, de-O-acylation, ESI-MS, acid hydrolysis, composition analysis, methanolysis, GPC, triflic acid solvolysis
  
   
  
  Providencia rustigianii O11:H10 157
  CSDB ID 28546 (all data & tools)

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Structure type: oligomer ; 734.2732 [M-H]-
C₂₉H₄₅N₅O₁₇
Compound class: CPS

• Article ID: 5789
  Kenyon JJ, Senchenkova SN, Shashkov AS, Shneider MM, Popova AV, Knirel YA, Hall RM "K17 capsular polysaccharide produced by Acinetobacter baumannii isolate G7 contains an amide of 2-acetamido-2-deoxy-D-galacturonic acid with D-alanine" - International Journal of Biological Macromolecules 144 (2020) 857-862
  

  The K17 capsular polysaccharide (CPS) produced by Acinetobacter baumannii G7, which carries the KL17 configuration at the capsule biosynthesis locus, was isolated and studied by chemical methods along with one- and two-dimensional 1H and 13C NMR spectroscopy. Selective cleavage of the glycosidic linkage of a 2,4-diacetamido-2,4,6-trideoxy-D-glucose (D-QuiNAc4NAc) residue by (i) trifluoroacetic acid solvolysis or (ii) alkaline β-elimination (NaOH-NaBH4) of the 4-linked D-alanine amide of a 2-acetamido-2-deoxy-D-galacturonic acid residue (d-GalNAcA6DAla) yielded trisaccharides that were isolated by Fractogel TSK HW-40 gel-permeation chromatography and identified by using NMR spectroscopy and high-resolution electrospray ionization mass spectrometry. The following structure was established for the trisaccharide repeat (K unit) of the CPS: →4)-α-D-GalpNAcA6DAla-(1→4)-α-D-GalpNAcA-(1→3)-β-D-QuipNAc4NAc-(1→. The presence of the itrA1 gene coding for the initial glycosylphosphotransferase in the KL17 gene cluster established the first sugar of the K unit as D-QuipNAc4NAc. KL17 includes genes for three transferases that had been annotated previously as glycosyltransferases (Gtrs). As only two Gtrs are required for the K17 structure and one D-GalpNAcA residue is modified by a D-alanine amide, these assignments were re-assessed. One transferase was found to belong to the ATPgrasp_TupA protein family that includes D-alanine-D-alanine ligases, and thus was renamed Alt1 (alanine transferase). Alt1 represents a novel family that amidate the carboxyl group of D-GalpNAcA or D-GalpA.

  Acinetobacter baumannii, capsular polysaccharide, D-alanine, K locus, KL17

  NCBI PubMed ID: 31715229
  Publication DOI: 10.1016/j.ijbiomac.2019.09.163
  Journal NLM ID: 7909578
  Publisher: Butterworth-Heinemann
  Correspondence: johanna.kenyon@qut.edu.au
  Institutions: N.D. Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, Russia, M. M. Shemyakin & Y. A. Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow, Russia, State Research Center for Applied Microbiology and Biotechnology, Obolensk, Moscow Region, Russia, Moscow Institute of Physics and Technology, Dolgoprudny, Moscow Region, Russia, Institute of Health and Biomedical Innovation, School of Biomedical Sciences, Faculty of Health, Queensland University of Technology, Brisbane, Australia, School of Life and Environmental Sciences, The University of Sydney, Sydney, Australia, Institute of Antimicrobial Chemotherapy, Smolensk State Medical University, Smolensk, Russia
  Methods: 13C NMR, NMR-2D, GLC, chemical methods, NMR-1D, GPC, bioinformatic analysis, solvolysis with trifluoroacetic acid, HR-ESI-MS1H NMR
  
   
  
  Acinetobacter baumannii K17 G7
  CSDB ID 4190 (all data & tools)