EC 6.3.4.21 - Nicotinate phosphoribosyltransferase
IntEnz view
ENZYME view
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
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
- nicotinate + 5-phospho-alpha-D-ribose 1-diphosphate + ATP + H2O = beta-nicotinate D-ribonucleotide + diphosphate + ADP + phosphate
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
Gene Ontology:
GO:0004516
CAS Registry Number:
9030-26-6
References
-
Pathway of diphosphopyridine nucleotide biosynthesis in Escherichia coli.J. Biol. Chem. 236 : 1494-1497 (1961). [PMID: 13717628]
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Biosynthesis of diphosphopyridine nucleotide. III. Nicotinic acid mononucleotide pyrophosphorylase.J. Biol. Chem. 236 : 525-530 (1961). [PMID: 13717627]
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Nicotinate phosphoribosyltransferase of yeast. Purification and properties.J. Biol. Chem. 246 : 3277-3283 (1971). [PMID: 4324895]
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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]