Diphtheria Toxin - Mechanism

Mechanism

The diphtheria toxin has the same mechanism of action as the enzyme NAD(+)—diphthamide ADP-ribosyltransferase (EC 2.4.2.36). It catalyzes the transfer of NAD+ to a diphthamide residue in eukaryotic elongation factor-2 (eEF2), inactivating this protein. It does so by ADP-ribosylating the unusual amino acid diphthamide. In this way, it acts as a RNA translational inhibitor. The catalysed reaction is as follows:

NAD+ + peptide diphthamide nicotinamide + peptide N-(ADP-D-ribosyl)diphthamide

The cholera toxin and exotoxin A of Pseudomonas aeruginosa uses a similar mechanism of action.

Read more about this topic:  Diphtheria Toxin

Famous quotes containing the word mechanism:

    The law isn’t justice. It’s a very imperfect mechanism. If you press exactly the right buttons and are also lucky, justice may show up in the answer. A mechanism is all the law was ever intended to be.
    Raymond Chandler (1888–1959)

    A mechanism of some kind stands between us and almost every act of our lives.
    Sarah Patton Boyle, U.S. civil rights activist and author. The Desegregated Heart, part 3, ch. 2 (1962)

    When one of us dies of cancer, loses her mind, or commits suicide, we must not blame her for her inability to survive an ongoing political mechanism bent on the destruction of that human being. Sanity remains defined simply by the ability to cope with insane conditions.
    Ana Castillo (b. 1953)