1bos: Difference between revisions

[[Image:1bos.gif|left|200px]]<br /><applet load="1bos" size="350" color="white" frame="true" align="right" spinBox="true"  

Shiga-like toxin I (SLT-I) is a virulence factor of Escherichia coli strains that cause disease in humans. Like other members of the Shiga toxin family, it consists of an enzymatic (A) subunit and five copies of a binding subunit (the B-pentamer). The B-pentamer binds to a specific glycolipid, globotriaosylceramide (Gb3), on the surface of target cells and thereby plays a crucial role in the entry of the toxin. Here we present the crystal structure at 2.8 A resolution of the SLT-I B-pentamer complexed with an analogue of the Gb3 trisaccharide. The structure reveals a surprising density of binding sites, with three trisaccharide molecules bound to each B-subunit monomer of 69 residues. All 15 trisaccharides bind to one side of the B-pentamer, providing further evidence that this side faces the cell membrane. The structural model is consistent with data from site-directed mutagenesis and binding of carbohydrate analogues, and allows the rational design of therapeutic Gb3 analogues that block the attachment of toxin to cells.

1BOS is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bacteriophage_h30,_bacteriophage_h19b Bacteriophage h30, bacteriophage h19b] with <scene name='pdbligand=GAL:'>GAL</scene> as [http://en.wikipedia.org/wiki/ligand ligand]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1BOS OCA].  

[[Category: Armstrong, G D.]]

[[Category: Brunton, J L.]]

[[Category: Cummings, M D.]]

[[Category: Read, R J.]]

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