CATH Classification

Domain Context

CATH Clusters

Superfamily nicotinate phosphoribosyltransferase
Functional Family Nicotinate phosphoribosyltransferase

Enzyme Information

6.3.4.21
Nicotinate phosphoribosyltransferase.
based on mapping to UniProt Q6XQN6
Nicotinate + 5-phospho-alpha-D-ribose 1-diphosphate + ATP + H(2)O = beta- nicotinate D-ribonucleotide + diphosphate + ADP + phosphate.
-!- The enzyme, which is involved in pyridine nucleotide recycling, can form beta-nicotinate D-ribonucleotide and diphosphate from nicotinate and 5-phospho-alpha-D-ribose 1-diphosphate (PRPP) in the absence of ATP. -!- However, when ATP is available the enzyme is phosphorylated resulting in a much lower K(m) for nicotinate. -!- The phospho-enzyme is hydrolyzed during the transferase reaction, regenerating the low affinity form. -!- The presence of ATP shifts the products/substrates equilibrium from 0.67 to 1100. -!- Formerly EC 2.4.2.11.

UniProtKB Entries (1)

Q6XQN6
PNCB_HUMAN
Homo sapiens
Nicotinate phosphoribosyltransferase

PDB Structure

PDB 4YUB
External Links
Method X-RAY DIFFRACTION
Organism
Primary Citation
Crystal structure of human nicotinic acid phosphoribosyltransferase.
Marletta, A.S., Massarotti, A., Orsomando, G., Magni, G., Rizzi, M., Garavaglia, S.
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