Can AB toxins have multiple A subunits?
The AB toxins are two-component protein complexes secreted by a number of pathogenic bacteria. They can be classified as Type III toxins because they interfere with internal cell function….AB toxin.
| Binary_toxB | |
|---|---|
| SCOP2 | 1acc / SCOPe / SUPFAM |
| TCDB | 1.C.42 |
| showAvailable protein structures: |
What is an AB type toxin?
Botulinum toxins are members of a broad class of bacterial toxic proteins, called AB toxins. These are secreted bacterial proteins that enter cells and exert their toxic effects by affecting intracellular processes. Other AB toxins include tetanus, cholera, anthrax, shiga and diphtheria toxins.
How does an AB exotoxin work?
Some A-B toxins work differently. This toxin interferes with host cell protein synthesis by catalyzing the ADP-ribosylation of host cell elongation factor 2 (EF-2), necessary in order for tRNA to insert new amino acids into the growing protein chain. This results in cell death.
Do all a toxins work the same way?
Further, not all organisms react to toxins in the same way. Each organisms, even within a species, is essentially a unique biochemical factory. Some organisms are better equipped to handle certain toxins than others. The specific effects of a toxin are determined by how it interacts with the cells of the organisms.
Are AB toxins heat stable?
Exotoxins. Exotoxins are typically heat sensitive (heat labile) proteins, but some are heat stable polypeptides. The structure of the toxin: e.g. AB toxins, which consist of two different protein subunits, A and B. A and B refers to active and binding, respectively, i.e. the actions of the subunits on the target cell.
What is exotoxin and endotoxin?
Classically, bacterial toxins are divided into exotoxins and endotoxins. While endotoxins are membrane compounds of Gram-negative bacteria which elicit an inflammatory response in host, exotoxins are secreted proteins which act locally and at distance of the bacterial colonization site.
Is cholera an AB toxin?
Cholera toxin (CT) is an AB-type protein toxin that contains a catalytic A1 subunit, an A2 linker, and a cell-binding B homopentamer. The CT holotoxin is released into the extracellular environment, but CTA1 attacks a target within the cytosol of a host cell.