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Taxonomic group: bacteria / Actinobacteria (Phylum: Actinobacteria)
Organ / tissue: cell wall

The structure was elucidated in this paper
NCBI PubMed ID: 16040600
Publication DOI: 10.1074/jbc.M506339200
Journal NLM ID: 2985121R
Publisher: Baltimore, MD: American Society for Biochemistry and Molecular Biology
Correspondence: g.besra

bham.ac.uk
Institutions: School of Biosciences, University of Birmingham, Birmingham, UK, Institute for Biotechnologie, Research Centre Juelich, Juelich, Germany, Division of Molecular Biosciences, Faculty of Life Sciences, Imperial College, London, UK, M-SCAN Mass Spectrometry Research and Training Centre, Silwood Park, Ascot, UK

The cell wall of Mycobacterium tuberculosis has a complex ultrastructure that consists of mycolic acids connected to peptidoglycan via arabinogalactan (AG) and abbreviated as the mAGP complex. The mAGP complex is crucial for the survival and pathogenicity of M. tuberculosis and is the target of several anti-tubercular agents. Apart from sharing a similar mAGP and the availability of the complete genome sequence, Corynebacterium glutamicum has proven useful in the study of orthologous M. tuberculosis genes essential for viability. Here we examined the effects of particular genes involved in AG polymerization by gene deletion in C. glutamicum. The anti-tuberculosis drug ethambutol is thought to target a set of arabinofuranosyltransferases (Emb) that are involved in arabinan polymerization. Deletion of emb in C. glutamicum results in a slow growing mutant with profound morphological changes. Chemical analysis revealed a dramatic reduction of arabinose resulting in a novel truncated AG structure possessing only terminal arabinofuranoside (t-Araf) residues with a corresponding loss of cell wall bound mycolic acids. Treatment of wild-type C. glutamicum with ethambutol and subsequent cell wall analyses resulted in an identical phenotype comparable to the C. glutamicum emb deletion mutant. Additionally, disruption of ubiA in C. glutamicum, the first enzyme involved in the biosynthesis of the sugar donor decaprenol phosphoarabinose (DPA), resulted in a complete loss of cell wall arabinan. Herein, we establish for the first time, (i) that in contrast to M. tuberculosis embA and embB mutants, deletion of C. glutamicum emb leads to a highly truncated AG possessing t-Araf residues, (ii) the exact site of attachment of arabinan chains in AG, and (iii) DPA is the only Araf sugar donor in AG biosynthesis suggesting the presence of a novel enzyme responsible for "priming" the galactan domain for further elaboration by Emb, resulting in the final maturation of the native AG polysaccharide.

biosynthesis, cell wall, arabinogalactan, Mycobacterium tuberculosis, mycolic acids

Structure type: structural motif or average structure
Location inside paper: Fig.8, A
Compound class: O-polysaccharide, arabinorhamnogalactan
Contained glycoepitopes: IEDB_136095,IEDB_136105,IEDB_137472,IEDB_1394181,IEDB_149137,IEDB_149176,IEDB_190606,IEDB_225177,IEDB_885812,IEDB_885823

Methods: methylation, DNA sequencing, GC-MS, acid hydrolysis, GC, MALDI-TOF MS, extraction, mutation analysis, cell growth, sonication
Comments, role: sequence of galactose substitution patterns (alternating 5- and 6-substitution) and arabinose substitution position were suggested by CSDB stuff

NCBI Taxonomy refs (TaxIDs): 196627
Show glycosyltransferases

There are 2 chemically distinct structures. Please, select:

C[C@H]1OC(O[C@H](CO)[C@@H]2O[C@@H](OC[C@@H](O)[C@@H]3O[C@@H](O[C@H](CO)[C@@H]4O[C@@H](OC[C@@H](O)[C@@H]5O[C@@H](O[C@H](CO)[C@@H]6O[C@@H](OC[C@@H](O)[C@@H]7O[C@@H](O[C@H](CO)[C@@H]8O[C@@H](O[C@H](CO[C@H]9O[C@H](CO)[C@@H](O)[C@@H]9O)[C@@H]9O[C@@H](O[C@H](CO)[C@@H]%10O[C@@H](O[C@H](CO[C@H]%11O[C@H](CO)[C@@H](O)[C@@H]%11O)[C@@H]%11O[C@@H](O[C@H](CO)[C@@H]%12O[C@@H](O[C@H](CO[C@H]%13O[C@H](CO)[C@@H](O)[C@@H]%13O)[C@@H]%13O[C@@H](O[C@H](CO)[C@@H]%14O[C@@H](OC[C@@H](O)[C@@H]%15O[C@@H](O[C@H](CO)[C@@H]%16O[C@@H](OC[C@@H](O)[C@@H]%17O[C@@H](O[C@H](CO)[C@@H]%18O[C@@H](OC[C@@H](O)[C@@H]%19O[C@@H](O[C@H](CO)[C@@H]%20O[C@@H](OC[C@@H](O)[C@@H]%21O[C@@H](O)[C@H](O)[C@H]%21O)[C@H](O)[C@H]%20O)[C@H](O)[C@H]%19O)[C@H](O)[C@H]%18O)[C@H](O)[C@H]%17O)[C@H](O)[C@H]%16O)[C@H](O)[C@H]%15O)[C@H](O)[C@H]%14O)[C@H](O)[C@H]%13O)[C@H](O)[C@H]%12O)[C@H](O)[C@H]%11O)[C@H](O)[C@H]%10O)[C@H](O)[C@H]9O)[C@H](O)[C@H]8O)[C@H](O)[C@H]7O)[C@H](O)[C@H]6O)[C@H](O)[C@H]5O)[C@H](O)[C@H]4O)[C@H](O)[C@H]3O)[C@H](O)[C@H]2O)[C@@H](O)[C@@H](O)[C@@H]1O

SVG MW SMILES 3D mol Ionize

Taxonomic group: plant / Streptophyta (Phylum: Streptophyta)
Organ / tissue: leaf

The structure was elucidated in this paper
NCBI PubMed ID: 2616672
Publication DOI: 10.1055/s-2006-962088
Journal NLM ID: 0066751
Publisher: George Thieme
Institutions: Departement of Pharmacy, University of Regensburg, Regensburg, Germany

The water-soluble polysaccharides from Cassia angustifolia L. leaves were isolated and fractionated. The acidic polysaccharide fraction was separated into two subfractions S1 and S2 consisting of L-rhamnose, L-arabinose, D-galactose, and D-galacturonic acid. Further fractionation of the predominant S1 by GPC gave two fractions S1A and S1B with an average molecular weight of 2000000 and 150000 Da, respectively. Methylation analysis of S1A showed the presence of 1,4-linked galacturonic acid (31.0%), 1,2-linked rhamnose (14.5%), 1,2,4-linked rhamnose (15.8%), 1,3,6-linked galactose (15.3%), smaller amounts of 1,3-linked arabinose, 1,5-linked arabinose, and terminal galactose and arabinose residues. Mild acid hydrolysis of S1A indicated that the backbone consists of 1,4-linked galacturonic acid and 1,2-linked rhamnose residues in the ratio of 1:1. Every second rhamnose is connected via C-4 to arabinogalactan sidechains. The antitumor activity of the polysaccharide fractions was tested against the solid Sarcoma-180 in CD1 mice. Only S1A exhibited a significant antitumor activity with an inhibition rate of 51%.

acidic polysaccharide, heteropolysaccharide, antitumor activity, Cassia angustifolia

Structure type: structural motif or average structure ; 2000000
Location inside paper: p. 538, Fig. 1
Compound class: polysaccharide, arabinorhamnogalactan
Contained glycoepitopes: IEDB_115013,IEDB_130645,IEDB_134624,IEDB_136044,IEDB_136105,IEDB_136906,IEDB_136907,IEDB_137472,IEDB_141794,IEDB_149558,IEDB_151528,IEDB_153201,IEDB_156493,IEDB_190606,IEDB_225177,IEDB_742246,IEDB_742248,IEDB_885823,IEDB_918313,IEDB_918314,SB_163,SB_165,SB_166,SB_187,SB_195,SB_7,SB_87,SB_88

Methods: methylation, GC-MS, acid hydrolysis, GPC, extraction, acetylation, uronic acid degradation, methylation analysis, reduction, CC, dialysis, antitumor activity assay, centrifugation, ion exchange chromatography, Blumenkrantz method
Biological activity: polysaccharide has no direct cytotoxic activity against Sarcoma-180 cells. The possible action of polysaccharide against Sarcoma-180 should be initiated through a stimulation of the hosts immune system

NCBI Taxonomy refs (TaxIDs): 72402
Show glycosyltransferases

There is only one chemically distinct structure:

*O[C@H]1[C@@H](C(=O)O)O[C@H](O[C@H]2[C@H](*)O[C@@H](C)[C@H](OC3O[C@H](COC4O[C@@H](CO)[C@H](OC5O[C@@H](CO)[C@H](O)[C@H]5O)[C@H]4O)[C@H](O)[C@H](OC4O[C@H](CO)[C@H](O)[C@H](O)[C@H]4O)[C@H]3O)[C@H]2O)[C@H](O)[C@H]1O

SVG MW SMILES 3D mol Ionize