7PRP

Crystal Structure of the B subunit of heat labile enterotoxin LT-IIc from Escherichia coli in apo form

This is a non-PDB format compatible entry.

Summary for 7PRP

• Entry DOI: 10.2210/pdb7prp/pdb
• Descriptor: Heat-labile enterotoxin IIA, B chain, SODIUM ION, FORMIC ACID, ... (4 entities in total)
• Functional Keywords: lectin, ganglioside, heat labile enterotoxin, sugar binding protein
• Biological source: Escherichia coli
• Total number of polymer chains: 5
• Total formula weight: 57752.97

Authors

Varrot, A. (deposition date: 2021-09-22, release date: 2021-12-08, Last modification date: 2024-11-06)

Primary citation

Zalem, D.,Juhas, M.,Terrinoni, M.,King-Lyons, N.,Lebens, M.,Varrot, A.,Connell, T.D.,Teneberg, S.
Characterization of the ganglioside recognition profile of Escherichia coli heat-labile enterotoxin LT-IIc.
Glycobiology, 32:391-403, 2022

PubMed Abstract: The heat-labile enterotoxins of Escherichia coli and cholera toxin of Vibrio cholerae are related in structure and function. Each of these oligomeric toxins is comprised of one A polypeptide and five B polypeptides. The B-subunits bind to gangliosides, which are followed by uptake into the intoxicated cell and activation of the host's adenylate cyclase by the A-subunits. There are two antigenically distinct groups of these toxins. Group I includes cholera toxin and type I heat-labile enterotoxin of E. coli; group II contains the type II heat-labile enterotoxins of E. coli. Three variants of type II toxins, designated LT-IIa, LT-IIb and LT-IIc have been described. Earlier studies revealed the crystalline structure of LT-IIb. Herein the carbohydrate binding specificity of LT-IIc B-subunits was investigated by glycosphingolipid binding studies on thin-layer chromatograms and in microtiter wells. Binding studies using a large variety of glycosphingolipids showed that LT-IIc binds with high affinity to gangliosides with a terminal Neu5Acα3Gal or Neu5Gcα3Gal, e.g. the gangliosides GM3, GD1a and Neu5Acα3-/Neu5Gcα3--neolactotetraosylceramide and Neu5Acα3-/Neu5Gcα3-neolactohexaosylceramide. The crystal structure of LT-IIc B-subunits alone and with bound LSTd/sialyl-lacto-N-neotetraose d pentasaccharide uncovered the molecular basis of the ganglioside recognition. These studies revealed common and unique functional structures of the type II family of heat-labile enterotoxins.

PubMed: 34972864
DOI: 10.1093/glycob/cwab133

Experimental method

X-RAY DIFFRACTION (2.3 Å)