View source for N-acetyllactosaminide beta-1,6-N-acetylglucosaminyl-transferase

{{enzyme
| Name = nicotinate-nucleotide diphosphorylase (carboxylating)
| EC_number = 2.4.2.19
| CAS_number = 37277-74-0
| IUBMB_EC_number = 2/4/2/19
| GO_code = 0004514
| image = 
| width = 
| caption = 
}}
In [[enzymology]], a '''nicotinate-nucleotide diphosphorylase (carboxylating)''' ({{EC number|2.4.2.19}}) is an [[enzyme]] that [[catalysis|catalyzes]] the [[chemical reaction]]

:nicotinate D-ribonucleotide + diphosphate + CO<sub>2</sub> <math>\rightleftharpoons</math> pyridine-2,3-dicarboxylate + 5-phospho-alpha-D-ribose 1-diphosphate

The 3 [[substrate (biochemistry)|substrates]] of this enzyme are [[nicotinate D-ribonucleotide]], [[diphosphate]], and [[carbon dioxide|CO<sub>2</sub>]], whereas its two [[product (chemistry)|products]] are [[pyridine-2,3-dicarboxylate]] and [[5-phospho-alpha-D-ribose 1-diphosphate]].

This enzyme belongs to the family of [[glycosyltransferase]]s, specifically the pentosyltransferases.  The systematic name of this enzyme class is '''nicotinate-nucleotide:diphosphate phospho-alpha-D-ribosyltransferase (carboxylating)'''. Other names in common use include '''quinolinate phosphoribosyltransferase (decarboxylating)''', '''quinolinic acid phosphoribosyltransferase''', '''QAPRTase''', '''NAD+ pyrophosphorylase''', '''nicotinate mononucleotide pyrophosphorylase (carboxylating)''', and '''quinolinic phosphoribosyltransferase'''.  This enzyme participates in [[nicotinate and nicotinamide metabolism]].  

==Structural studies==

As of late 2007, 9 [[tertiary structure|structures]] have been solved for this class of enzymes, with [[Protein Data Bank|PDB]] accession codes {{PDB link|1QAP}}, {{PDB link|1QPN}}, {{PDB link|1QPO}}, {{PDB link|1QPQ}}, {{PDB link|1QPR}}, {{PDB link|1X1O}}, {{PDB link|2B7N}}, {{PDB link|2B7P}}, and {{PDB link|2B7Q}}.

==References==
{{reflist|1}}
* {{cite journal | author = GHOLSON RK, UEDA I, OGASAWARA N, HENDERSON LM | date = 1964 | title = THE ENZYMATIC CONVERSION OF QUINOLINATE TO NICOTINIC ACID MONONUCLEOTIDE IN MAMMALIAN LIVER | journal = J. Biol. Chem.  | volume = 239 | pages = 1208&ndash;14  | pmid = 14165928 }}
* {{cite journal | author = Packman PM, Jakoby WB | date = 1965 | title = Crystalline quinolinate phosphoribosyltransferase | journal = J. Biol. Chem.  | volume = 240 | pages = 4107&ndash;8  | pmid = 5320648 | issue = 10 }}

{{enzyme-stub}}

[[Category:EC 2.4.2]]
[[Category:Enzymes of known structure]]