Structural highlights
Function
[STXB_SHIDY] The B subunit is responsible for the binding of the holotoxin to specific receptors on the target cell surface, such as globotriaosylceramide (Gb3) in human intestinal microvilli.[1]
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
Shigella dysenteriae is the pathogen responsible for the severe form of dysentery in humans. It produces Shiga toxin, the prototype of a family of closely related bacterial protein toxins. We have determined the structure of the holotoxin, an AB5 hexamer, by X-ray crystallography. The five B subunits form a pentameric ring, encircling a helix at the carboxy terminus of the A subunit. The A subunit interacts with the B pentamer via this C-terminal helix and a four-stranded mixed beta-sheet. The fold of the rest of the A subunit is similar to that of the A chain of the plant toxin ricin; both are N-glycosidases. However, the active site in the bacterial holotoxin is blocked by a segment of polypeptide chain. These residues of the A subunit would be released as part of the activation mechanism of the toxin.
Crystal structure of the holotoxin from Shigella dysenteriae at 2.5 A resolution.,Fraser ME, Chernaia MM, Kozlov YV, James MN Nat Struct Biol. 1994 Jan;1(1):59-64. PMID:7656009[2]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
See Also
References
- ↑ Donohue-Rolfe A, Jacewicz M, Keusch GT. Isolation and characterization of functional Shiga toxin subunits and renatured holotoxin. Mol Microbiol. 1989 Sep;3(9):1231-6. PMID:2677606
- ↑ Fraser ME, Chernaia MM, Kozlov YV, James MN. Crystal structure of the holotoxin from Shigella dysenteriae at 2.5 A resolution. Nat Struct Biol. 1994 Jan;1(1):59-64. PMID:7656009
