Biology:NAD(+)—diphthamide ADP-ribosyltransferase

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Short description: Class of enzymes
NAD+-diphthamide ADP-ribosyltransferase
Identifiers
EC number2.4.2.36
CAS number52933-21-8
Databases
IntEnzIntEnz view
BRENDABRENDA entry
ExPASyNiceZyme view
KEGGKEGG entry
MetaCycmetabolic pathway
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBsum
Gene OntologyAmiGO / QuickGO

In enzymology, a NAD+-diphthamide ADP-ribosyltransferase (EC 2.4.2.36) is an enzyme that catalyzes the chemical reaction

NAD+ + peptide diphthamide [math]\displaystyle{ \rightleftharpoons }[/math] nicotinamide + peptide N-(ADP-D-ribosyl)diphthamide

Thus, the two substrates of this enzyme are NAD+ and peptide diphthamide, whereas its two products are nicotinamide and peptide N-(ADP-D-ribosyl)diphthamide.

This enzyme belongs to the family of glycosyltransferases, to be specific, the pentosyltransferases. The systematic name of this enzyme class is NAD+:peptide-diphthamide N-(ADP-D-ribosyl)transferase. Other names in common use include ADP-ribosyltransferase, mono(ADPribosyl)transferase, and NAD-diphthamide ADP-ribosyltransferase.

Structural studies

As of late 2007, 15 structures have been solved for this class of enzymes, with PDB accession codes 1S5B, 1S5C, 1S5D, 1S5E, 1S5F, 1SGK, 1TOX, 1XDT, 1XK9, 1ZM3, 1ZM4, 1ZM9, 2A5D, 2A5F, and 2A5G.

Clinical significance

The extracellular ADP-ribosyl-transferase ART2 is expressed only on T cells.[1] T cell activation of P2X7 receptors can activate the T cells or cause T cell differentiation, can affect T cell migration or (at high extracellular levels of NAD+) can induce cell death by ART2.[1]

References

See also