EC 6.3.4.21 - Nicotinate phosphoribosyltransferase

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IntEnz Enzyme Nomenclature
EC 6.3.4.21

Names

Accepted name:
nicotinate phosphoribosyltransferase
Other names:
niacin ribonucleotidase
nicotinic acid mononucleotide glycohydrolase
nicotinic acid mononucleotide pyrophosphorylase
nicotinic acid phosphoribosyltransferase
nicotinate-nucleotide:diphosphate phospho-α-D-ribosyltransferase
Systematic name:
5-phospho-α-D-ribose 1-diphosphate:nicotinate ligase (ADP, diphosphate-forming)

Reaction

Comments:

The enzyme, which is involved in pyridine nucleotide recycling, can form β-nicotinate D-ribonucleotide and diphosphate from nicotinate and 5-phospho-α-D-ribose 1-diphosphate (PRPP) in the absence of ATP. However, when ATP is available the enzyme is phosphorylated resulting in a much lower Km for nicotinate. The phospho-enzyme is hydrolysed during the transferase reaction, regenerating the low affinity form. The presence of ATP shifts the products/substrates equilibrium from 0.67 to 1100 [4].

Links to other databases

Enzymes and pathways: NC-IUBMB , BRENDA , DIAGRAM , ExplorEnz , ENZYME@ExPASy , KEGG , MetaCyc , UniPathway
Structural data: CSA , EC2PDB
Gene Ontology: GO:0004516
CAS Registry Number: 9030-26-6
UniProtKB/Swiss-Prot: (163) [show] [UniProt]

References

  1. Imsande, J.
    Pathway of diphosphopyridine nucleotide biosynthesis in Escherichia coli.
    J. Biol. Chem. 236: 1494-1497 (1961). [PMID: 13717628]
  2. Imsande, J. and Handler, P.
    Biosynthesis of diphosphopyridine nucleotide. III. Nicotinic acid mononucleotide pyrophosphorylase.
    J. Biol. Chem. 236: 525-530 (1961). [PMID: 13717627]
  3. Kosaka, A., Spivey, H.O. and Gholson, R.K.
    Nicotinate phosphoribosyltransferase of yeast. Purification and properties.
    J. Biol. Chem. 246: 3277-3283 (1971). [PMID: 4324895]
  4. Vinitsky, A., Grubmeyer, C.
    A new paradigm for biochemical energy coupling. Salmonella typhimurium nicotinate phosphoribosyltransferase.
    J. Biol. Chem. 268: 26004-26010 (1993). [PMID: 7503993]

[EC 6.3.4.21 created 1961 as EC 2.4.2.11, transferred 2013 to EC 6.3.4.21]