Nicotinate-nucleotide pyrophosphorylase (IPR004393)

Short name: NadC

Overlapping homologous superfamilies

Family relationships


Nicotinate-nucleotide pyrophosphorylase (EC:, also known as quinolinate phosphoribosyltransferase (decarboxylating), catalyses the conversion of nicotinate D-ribonucleotide, pyrophosphate and carbon dioxide into pyridine-2,3-dicarboxylate and 5-phospho-alpha-D-ribose 1-diphosphate. This enzyme is a type II phosphoribosyltransferase which provides the de novo source of nicotinate mononucleotide (NAMN) for NAD biosynthesis in both prokaryotes and eukaryotes [PMID: 6997723, PMID: 11876660].

Structural studies have shown that the active form of this enzyme is a homodimer with an unsual fold [PMID: 9016724, PMID: 9862811, PMID: 15103640]. The N-terminal forms a mixed alpha/beta domain, while the C-terminal region forms a multi-stranded, open alpha/beta barrel. The active site is found at the C-terminal ends of the beta strands of the alpha/beta barrel, and is bordered by the N-terminal domain of the second subunit of the dimer. It contains several conserved charged residues thought to be important determinants of substrate binding and catalysis.

GO terms

Biological Process

GO:0019363 pyridine nucleotide biosynthetic process

Molecular Function

GO:0004514 nicotinate-nucleotide diphosphorylase (carboxylating) activity

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.