Diphtheria toxin ADP-ribosyltransferase (DT)

Diphtheria toxin ADP-ribosyltransferase refers to the catalytic activity of diphtheria toxin, an exotoxin secreted by Corynebacterium diphtheriae. This enzyme catalyzes the transfer of an ADP-ribose group from NAD⁺ to a specific diphthamide residue on eukaryotic elongation factor 2 (eEF-2) in host cells, effectively inactivating eEF-2 and thereby halting protein synthesis. The result is cell death, which underlies the pathogenesis of diphtheria. This activity is the defining property of the "DT group" of bacterial ADP-ribosyltransferase toxins (bARTTs)[1][5]. Diphtheria toxin is a highly potent bacterial virulence factor, not an endogenous mammalian target. While it is a mechanistic enzyme, it is not a therapeutic target in the classic sense; medical interventions are aimed at neutralizing the toxin rather than inhibiting its activity directly[1][2][5]. Notes on correctness: - The entity named "Diphtheria toxin ADP-ribosyltransferase activity" describes an enzymatic function rather than a precise protein or druggable target; hence, it is not a canonical therapeutic target[3]. - The canonical protein is Diphtheria toxin, and the activity is its enzymatic function[4]. - No small-molecule inhibitors are in therapeutic use; treatment and prevention are via antitoxin and vaccination.

Other names

diphtheria toxinDTDiphtheria toxin catalytic domainDtx

Catalyzes transfer of ADP-ribose from NAD⁺ to diphthamide residue of eEF-2, leading to inactivation of eEF-2 and inhibition of protein synthesis[1][5][4]