2wv6

CRYSTAL STRUCTURE OF THE CHOLERA TOXIN-LIKE B-SUBUNIT FROM CITROBACTER FREUNDII TO 1.9 ANGSTROM

spinqualitylabelsall models 2wv6, resolution 1.90Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 2wv6 is a 10 chain structure with sequence from Citrobacter freundii. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Ligands: EDO, GOL Resources: FirstGlance, OCA, RCSB, PDBsum Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMed Enterotoxigenic Escherichia coli and Vibrio cholerae are well known causative agents of severe diarrheal diseases. Both pathogens produce AB(5) toxins, with one enzymatically active A-subunit and a pentamer of receptor-binding B-subunits. The primary receptor for both B-subunits is the GM1 ganglioside (Galbeta3GalNAcbeta4(NeuAcalpha3)Galbeta4GlcbetaCer), but the B-subunits from porcine isolates of E. coli also bind neolacto-(Galbeta4GlcNAcbeta-)terminated glycoconjugates and the B-subunits from human isolates of E. coli (hLTB) have affinity for blood group A type 2-(GalNAcalpha3(Fucalpha2)Galbeta4GlcNAcbeta-)terminated glycoconjugates. A B-subunit with 73% sequence identity to the B-subunits of cholera toxin and the heat-labile toxin of E. coli is produced by certain strains of enteropathogenic E. coli and by Citrobacter freundii. This C. freundii B-subunit (CFXB) has now been expressed in V. cholerae, and isolated in high yields. Glycosphingolipid binding studies show that CFXB binds to the GM1 ganglioside with high affinity. In addition, CFXB has high affinity for both neolacto-terminated and blood group A type 2-terminated glycoconjugates. The crystal structure of the pentameric arrangement of C. freundii B-subunits display high structural similarity with related proteins from E. coli and V. cholerae and oligosaccharide binding sites can be identified on the protein surface. Small changes in the 88-95 loop connecting the GM1 and blood group A binding sites explains the minor changes in affinity seen for these two ligands. However, the enhanced affinity of CFXB for neolacto-terminated structures can be sought in the Lys34Tyr substitution affording additional hydrogen bond interactions between the tyrosyl side chain and the GlcNAcbeta3Galb4Glcbeta1 segment of neolactotetraosylceramide via bridging water molecules. Carbohydrate binding specificities and crystal structure of the cholera toxin-like B-subunit from Citrobacter freundii.,Jansson L, Angstrom J, Lebens M, Imberty A, Varrot A, Teneberg S Biochimie. 2010 May;92(5):482-90. Epub 2010 Feb 18. PMID:20171259 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

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