Which of the following are AB5 toxins?

The mechanism pathways for the four AB5 toxins: cholera toxin, pertussis toxin, shiga toxin, and subtilase cytotoxin.

Is botulinum toxin an AB5 toxin?

botulinum is a zinc-dependent metalloprotease that cleave neuron-specific proteins (see below). Diphtheria toxin (DT) is an A-B toxin produced by Corynebacterium diphtheriae as a 58 kDA mature protein.

Is shiga toxin AB5?

3.1. 2 Shiga-like toxin and cholera toxin. Shiga-like toxin (SLT) and CT belong to bacterial AB5 toxin family that contains an enzymatically active A subunit and a doughnut-shaped pentameric B-subunit with 15 carbohydrate binding sites (3 sites per monomer).

What diseases are caused by 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.

What is the difference between cytotoxin and enterotoxin?

Pathogenic strains of C difficile produce 2 distinct toxins. Toxin A is an enterotoxin, and toxin B is a cytotoxin; both are high–molecular weight proteins capable of binding to specific receptors on the intestinal mucosal cells.

What does the cholera toxin do to the body?

The combined effects result in rapid fluid loss from the intestine, up to 2 liters per hour, leading to severe dehydration and other factors associated with cholera, including a rice-water stool.

What are the components of the AB 5 Toxin?

The AB 5 toxins are six-component protein complexes secreted by certain pathogenic bacteria known to cause human diseases such as cholera, dysentery, and hemolytic-uremic syndrome. One component is known as the A subunit, and the remaining five components are B subunits.

How did the AB toxin get its name?

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. The “A” subunit possesses enzyme activity, and is transferred to the host cell following a conformational change in the membrane-bound transport “B” subunit.

Where does Neu5Gc and AB5 toxin come from?

Neu5GC is not made by humans but is acquired from food sources such as red meat and dairy products, also frequent sources of STEC infections, into the human gut lining. A complete AB5 toxin complex contains six protein units. Five units are similar or identical in structure and they comprise the B subunit.

How does the AB toxin enter the cell?

These proteins consist of two independent polypeptides, which correspond to the A/B subunit moieties. The enzyme component (A) enters the cell through endosomes produced by the oligomeric binding/translocation protein (B), and prevents actin polymerisation through ADP-ribosylation of monomeric G-actin.