Nicotinamide phosphoribosyltransferase

In enzymology, a nicotinamide phosphoribosyltransferase is an enzyme that catalyzes the chemical reaction


 * nicotinamide D-ribonucleotide + diphosphate $$\rightleftharpoons$$ nicotinamide + 5-phospho-alpha-D-ribose 1-diphosphate

Thus, the two substrates of this enzyme are nicotinamide D-ribonucleotide and diphosphate, whereas its two products are nicotinamide and 5-phospho-alpha-D-ribose 1-diphosphate.

This enzyme belongs to the family of glycosyltransferases, specifically the pentosyltransferases. The systematic name of this enzyme class is nicotinamide-nucleotide:diphosphate phospho-alpha-D-ribosyltransferase. Other names in common use include NMN pyrophosphorylase, nicotinamide mononucleotide pyrophosphorylase, nicotinamide mononucleotide synthetase, and NMN synthetase. This enzyme participates in nicotinate and nicotinamide metabolism.

Structural studies
As of late 2007, 8 structures have been solved for this class of enzymes, with PDB accession codes, , , , , , , and.