What is an example of an AB toxin?
Examples of A-B toxins include: Diphtheria exotoxin, produced by Corynebacterium diphtheriae (inf). 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.
Which of the following are AB toxins?
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.
Which type of bacteria produces an AB toxin?
Anthrax is an AB enterotoxin produced by the Gram positive bacteria, Bacillus anthracis. Unlike other AB toxins described thus far in this review, anthrax toxin has a tripartite structure, consisting of three independent polypeptide chains.
What are examples of Exotoxins?
(Science: protein) toxin released from gram-positive and gram-negative bacteria as opposed to endotoxins that form part of the cell wall. Examples are cholera, pertussis and diphtheria toxins. Usually specific and highly toxic.
What are the 3 basic types of AB toxins?
anthracis secretes three toxin factors: the protective antigen (PA); the oedema factor (EF); and the lethal factor (LF).
Why is this called an AB toxin?
The AB toxins are two-component protein complexes secreted by a number of pathogenic bacteria. They are named AB toxins due to their components: the “A” component is usually the “active” portion, and the “B” component is usually the “binding” portion.
Which type of toxin is Shiga toxin?
Shiga toxin (Stx) is one of the most potent bacterial toxins known. Stx is found in Shigella dysenteriae 1 and in some serogroups of Escherichia coli (called Stx1 in E. coli).
Which of these diseases are caused by AB toxins?
Other AB toxins include tetanus, cholera, anthrax, shiga and diphtheria toxins. They are called AB toxins because they have two component parts. The A component contains an enzymatic activity that acts on intracellular targets.
Is botulinum toxin an AB toxin?
What are toxin A and B of Clostridium?
Structure and Function of Toxin A and Toxin B. Toxin A and toxin B are both members of the large clostridial glucosylating toxin family, which also includes lethal toxin (TcsL) and hemorrhagic toxin (TcsH) from Clostridium sordellii, alpha toxin (TcnA) from Clostridium novyi and TpeL from Clostridium perfringens.
Which is the best example of an AB toxin?
AB Toxin 1 Exploiting endocytic pathways to prevent bacterial toxin infection. Callista B. 2 Large clostridial cytotoxins modifying small GTpases. 3 Pasteurella multocida toxin. 4 Pasteurella multocida toxin. 5 Shiga toxins.
What are the names of the Clostridium difficile toxins?
The family of large clostridial cytotoxins resembles major virulence factors, including Clostridium difficile toxins A (TcdA) and B (TcdB), Clostridium sordellii lethal toxin (TcsL) and hemorrhaging toxin (TcsH), Clostridium novyi α-toxin (TcnA), and Clostridium perfringens toxin TpeL.
How is the AB toxin transferred to the host cell?
AB toxin. The “A” subunit possesses enzyme activity, and is transferred to the host cell following a conformational change in the membrane-bound transport “B” subunit. Among the toxins produced by certain Clostridium spp. are the binary exotoxins. These proteins consist of two independent polypeptides, which correspond to the A/B subunit moieties.
