1 Found In
DB identifier | Type | Name |
---|---|---|
IPR000512 | Family | Diphtheria toxin (NAD+-dipthamide ADP-ribosyltransferase) |
Type: | Domain | Name: | Diphtheria toxin, receptor-binding domain |
Description: | This entry represents the C-terminal receptor-binding domain, also known as the R domain. This domain has a beta-sandwich fold consisiting of nine strands in two sheet with greek-key topology; it is a subclass of immunoglobin-like fold []. The R domain binds to cell surface receptor, permitting the toxin to enter the cell by receptor mediated endocytosis [, ].Diphtheria toxin () is a 58 kDa protein secreted by lysogenic strains of Corynebacterium diphtheriae. The toxin causes the disease diphtheria in humans by gaining entry into the cell cytoplasm and inhibiting protein synthesis []. The mechanism of inhibition involves transfer of the ADP-ribose group of NAD to elongation factor-2 (EF-2), rendering EF-2 inactive. The catalysed reaction is as follows: NAD++ peptide diphthamide = nicotinamide + peptide N-(ADP-D-ribosyl)diphthamide The crystal structure of the diphtheria toxin homodimer has been determined to 2.5A resolution []. The structure reveals a Y-shaped molecule of 3 domains, a catalytic domain (fragment A), whose fold is of the alpha + beta type; a transmembrane (TM) domain, which consists of 9 alpha-helices, 2 pairs of which may participate in pH-triggered membrane insertion and translocation; and a receptor-binding domain, which forms a flattened beta-barrel with a jelly-roll-like topology []. The TM- and receptor binding-domains together constitute fragment B. | Short Name: | Diphtheria_toxin_rcpt-bd_dom |
DB identifier | Type | Name |
---|---|---|
IPR000512 | Family | Diphtheria toxin (NAD+-dipthamide ADP-ribosyltransferase) |