CSDB: Search results

Taxonomic group: bacteria / Firmicutes (Phylum: Firmicutes)
Associated disease: neonatal septicemia [ICD11: KA60

, Life stage: neonatal]; meningitis [ICD11: 1D01

]; infection due to Streptococcus agalactiae [ICD11: XN0KC

]

NCBI PubMed ID: 30781826
Publication DOI: 10.3390/ph12010028
Journal NLM ID: 101238453
Publisher: Basel, Switzerland: MDPI
Correspondence: mkuttel

cs.uct.ac.za; neil.ravenscroft

uct.ac.za
Institutions: Department of Computer Science, University of Cape Town, Cape Town 7701, South Africa, Department of Chemistry, University of Cape Town, Cape Town 7701, South Africa

Although the branched capsular polysaccharides of Streptococcus agalactiae serotype III (GBSIII PS) and Streptococcus pneumoniae serotype 14 (Pn14 PS) differ only in the addition of a terminal sialic acid on the GBSIII PS side chains, these very similar polysaccharides are immunogenically distinct. Our simulations of GBSIII PS, Pn14 PS and the unbranched backbone polysaccharide provide a conformational rationale for the different antigenic epitopes identified for these PS. We find that side chains stabilize the proximal βDGlc(1→6)βDGlcNAc backbone linkage, restricting rotation and creating a well-defined conformational epitope at the branch point. This agrees with the glycotope structure recognized by an anti-GBSIII PS functional monoclonal antibody. We find the same dominant solution conformation for GBSIII and Pn14 PS: aside from the branch point, the backbone is very flexible with a 'zig-zag' conformational habit, rather than the helix previously proposed for GBSIII PS. This suggests a common strategy for bacterial evasion of the host immune system: a flexible backbone that is less perceptible to the immune system, combined with conformationally-defined branch points presenting human-mimic epitopes. This work demonstrates how small structural features such as side chains can alter the conformation of a polysaccharide by restricting rotation around backbone linkages.

conformation, serotype, Streptococcus, Streptococcus pneumoniae, capsular polysaccharide, group B Streptococcus, molecular modeling, conjugate vaccines, carbohydrate antigen

Structure type: polymer chemical repeating unit
Location inside paper: fig.2, GBS serotype III PS (GBSIII PS)
Trivial name: PS-III
Compound class: CPS, EPS, polysaccharide
Contained glycoepitopes: IEDB_1083493,IEDB_1083495,IEDB_130646,IEDB_130697,IEDB_135813,IEDB_136044,IEDB_136794,IEDB_137340,IEDB_137472,IEDB_137776,IEDB_1391966,IEDB_1392542,IEDB_140108,IEDB_140110,IEDB_140122,IEDB_141794,IEDB_141807,IEDB_142344,IEDB_142351,IEDB_142487,IEDB_142488,IEDB_143634,IEDB_146100,IEDB_146107,IEDB_146664,IEDB_149138,IEDB_149139,IEDB_149141,IEDB_149142,IEDB_149143,IEDB_149144,IEDB_149145,IEDB_149147,IEDB_149148,IEDB_149149,IEDB_149150,IEDB_149151,IEDB_149174,IEDB_150933,IEDB_151531,IEDB_161524,IEDB_190606,IEDB_423120,IEDB_983931,SB_115,SB_116,SB_131,SB_145,SB_165,SB_166,SB_170,SB_171,SB_172,SB_173,SB_187,SB_192,SB_195,SB_30,SB_39,SB_6,SB_68,SB_7,SB_84,SB_88

Methods: 13C NMR, 1H NMR, NMR-2D, conformation analysis, MD simulations, molecular modeling
Comments, role: Streptococcus agalactiae serotype III (Group B Streptococcus, GBSIII PS).
3D data: molecular modeling

Related record ID(s): 1058
NCBI Taxonomy refs (TaxIDs): 216495
Reference(s) to other database(s): GTC:G35073UM, GlycomeDB:11408, CCSD:43274, CBank-STR:17387
Show glycosyltransferases

There is only one chemically distinct structure:

*O[C@@H]1[C@@H](CO)O[C@@H](OC[C@H]2O[C@@H](O[C@@H]3[C@@H](O)[C@H](*)O[C@H](CO)[C@@H]3O)[C@H](NC(C)=O)[C@@H](O)[C@@H]2O[C@@H]2O[C@H](CO)[C@H](O)[C@H](O[C@]3(C(=O)O)C[C@H](O)[C@@H](NC(C)=O)[C@H]([C@H](O)[C@H](O)CO)O3)[C@H]2O)[C@H](O)[C@H]1O

SVG MW SMILES 3D mol Ionize