2O2L

Crystal structure of human heat-labile enterotoxin in complex with a blood group A antigen analog

Summary for 2O2L

• Entry DOI: 10.2210/pdb2o2l/pdb
• Related: 2NZG
• Descriptor: Heat-labile enterotoxin B chain, alpha-L-fucopyranose-(1-2)-[2-acetamido-2-deoxy-alpha-D-galactopyranose-(1-3)]beta-D-galactopyranose-(1-4)-[alpha-L-fucopyranose-(1-3)]beta-D-glucopyranose (3 entities in total)
• Functional Keywords: enterotoxigenic e. coli, heat-labile enterotoxin, blood group antigen, toxin
• Biological source: Escherichia coli
• Total number of polymer chains: 10
• Total formula weight: 125692.11

Authors

Holmner, A.,Askarieh, G.,Okvist, M.,Krengel, U. (deposition date: 2006-11-30, release date: 2007-08-14, Last modification date: 2024-11-20)

Primary citation

Holmner, A.,Askarieh, G.,Okvist, M.,Krengel, U.
Blood Group Antigen Recognition by Escherichia coli Heat-labile Enterotoxin
J.Mol.Biol., 371:754-764, 2007

PubMed Abstract: In a number of bacterial infections, such as Helicobacter pylori, Campylobacter jejuni and Vibrio cholerae infections, a correlation between the severity of disease and blood group phenotype of infected individuals has been observed. In the present investigation, we have studied the molecular basis of this effect for enterotoxigenic Escherichia coli (ETEC) infections. ETEC are non-invasive bacteria, which act through second messenger pathways to cause diarrhea. It has been suggested that the major virulence factor of ETEC from human isolates, i.e. the human heat-labile enterotoxin (hLT), recognizes certain blood group epitopes, although the molecular basis of blood group antigen recognition is unknown. The 2.5 A crystal structure of the receptor-binding B-subunit of hLT in complex with the blood group A antigen analog GalNAcalpha3(Fucalpha2)Galbeta4(Fucalpha3)Glcbeta provides evidence of a previously unknown binding site in the native toxin. The structure reveals the molecular interactions underlying blood group antigen recognition and suggests how this protein can discriminate between different blood group epitopes. These results support the previously debated role of hLT in the blood group dependence of ETEC infections. Similar observations regarding the closely related cholera toxin in V. cholera infections are also discussed.

PubMed: 17586525
DOI: 10.1016/j.jmb.2007.05.064

Experimental method

X-RAY DIFFRACTION (2.53 Å)