Editing Shiga toxin (section)

=== Structure ===
The toxin has two subunits—designated A ([[Molecular mass|mol. wt.]] 32000 Da) and B (mol. wt. 7700 Da)—and is one of the [[AB5 toxin|AB<sub>5</sub> toxins]]. The B subunit is a [[oligomer|pentamer]] that binds to specific [[glycolipid]]s on the host cell, specifically [[globotriaosylceramide]] (Gb3).<ref name="pmid_1741063">{{cite journal | vauthors = Stein PE, Boodhoo A, Tyrrell GJ, Brunton JL, Read RJ | title = Crystal structure of the cell-binding B oligomer of verotoxin-1 from E. coli | journal = Nature | volume = 355 | issue = 6362 | pages = 748–50 | date = February 1992 | pmid = 1741063 | doi = 10.1038/355748a0 | bibcode = 1992Natur.355..748S | s2cid = 4274763 }}</ref><ref>{{cite journal | vauthors = Kaper JB, Nataro JP, Mobley HL | title = Pathogenic Escherichia coli | journal = Nature Reviews. Microbiology | volume = 2 | issue = 2 | pages = 123–40 | date = February 2004 | pmid = 15040260 | doi = 10.1038/nrmicro818 | s2cid = 3343088 }}</ref>   Following this, the A subunit is internalised and cleaved into two parts. The A1 component then binds to the ribosome, disrupting protein synthesis.  Stx-2 has been found to be about 400 times more toxic (as quantified by LD<sub>50</sub> in mice) than Stx-1.

Gb3 is, for unknown reasons, present in greater amounts in renal epithelial tissues, to which the renal toxicity of Shiga toxin may be attributed. Gb3 is also found in central nervous system neurons and endothelium, which may lead to [[neurotoxicity]].<ref name=Obata_2008>{{cite journal | vauthors = Obata F, Tohyama K, Bonev AD, Kolling GL, Keepers TR, Gross LK, Nelson MT, Sato S, Obrig TG | title = Shiga toxin 2 affects the central nervous system through receptor globotriaosylceramide localized to neurons | journal = The Journal of Infectious Diseases | volume = 198 | issue = 9 | pages = 1398–406 | date = November 2008 | pmid = 18754742 | pmc = 2684825 | doi = 10.1086/591911 }}</ref>
Stx-2 is also known to increase the expression of its receptor GB3 and cause neuronal dysfunctions.<ref name=Tironi-Farinati_2010>{{cite journal | vauthors = Tironi-Farinati C, Loidl CF, Boccoli J, Parma Y, Fernandez-Miyakawa ME, Goldstein J | title = Intracerebroventricular Shiga toxin 2 increases the expression of its receptor globotriaosylceramide and causes dendritic abnormalities | journal = Journal of Neuroimmunology | volume = 222 | issue = 1–2 | pages = 48–61 | date = May 2010 | pmid = 20347160 | doi = 10.1016/j.jneuroim.2010.03.001 | s2cid = 11910897 | hdl = 11336/16303 | hdl-access = free }}</ref>