Diphtheria toxin

<StructureSection load='' size='350' side='right' caption='Structure of diphtheria toxin complex with adenylyl-UMP (PDB code [[1ddt]]).' scene='59/592684/Cv/4'>

'''Diphtheria toxin''' (DT) is a toxin which is secreted by the bacteria causing diphtheria. DT catalyzes the transfer of NAD to a diphthamide residue in the elongation factor-2 and thus inhibiting protein synthesis.<ref>PMID:20040</ref> See also [[Toxins]].

DT is used in several drugs as chemotherapeutic agent and as an immunotoxin.

<scene name='59/592684/Cv/17'>The biological assembly of Diphtheria toxin is dimer</scene>. DT is proteolitically cleaved into 2 fragments. <scene name='59/592684/Cv/7'>Fragment A contains the catalytic domain (C)</scene> and <scene name='59/592684/Cv/8'>fragment B</scene> contains the <scene name='59/592684/Cv/9'>transmembrane (T)</scene> and <scene name='59/592684/Cv/10'>receptor-binding (R)</scene> domains. <scene name='59/592684/Cv/19'>DT active site</scene> is located in a cleft in the C domain.<ref>PMID:7833807</ref> Water molecules are shown as red spheres. The 2 monomers of DT interact by domain swapping to form a <scene name='59/592684/Cv/16'>compact, globular dimer structure</scene>.

</StructureSection>

{{#tree:id=OrganizedByTopic|openlevels=0|

**[[1ddt]], [[1mdt]], [[1f0l]] – CdDT + adenylyl phosphor-UMP <br />

**[[1tox]] – CdDT + NAD<br />

**[[4ae1]] – CdDT (mutant) + nicotinamide<br />

**[[1xdt]] – CdDT + heparin-binding epidermal growth factor<br />

**[[1dtp]] – CdDT catalytic domain + adenylyl phosphor-UMP <br />

}}