Center for Bioinformatics
Oxidoreductases | Transferases | Hydrolases | Lyases | Isomerases | Ligases

Basic Information

Enzyme Number

2.4.2.7

Official Name

adenine phosphoribosyltransferase

Name from literature

adenine phosphoribosyl transferase

Pathway from literature

AMP formation and subsequently the formation of ADP and ATP

Pathway from KEGG

Nucleotide Metabolism; Purine metabolism; map00230

Organisms

Human (9606)

Genome localization

16q24[353 ],

Comments

5-Amino-4-imidazolecarboxamide can replace adenine.

Rate-limiting Description

"Relative to normal brain the tumors had significantly lower ATP and GTP levels, essentially normal pool sizes of purine nucleosides and bases, unchanged activities of the salvage enzymes hypoxanthine-guanine phosphoribosyltransferase, adenine phosphoribosyltransferase, and adenosine kinase (659, 456, and 98 nmol/h/mg protein, respectively) and 4-fold higher activities of IMP dehydrogenase (11.6 nmol/h/mg protein); the latter is the rate limiting enzyme for guanylate de novo synthesis." (2154328)

"The reciprocal plots for 5-phosphoribosyl-1-pyrophosphate (PRPP) of liver and hepatoma enzymes gave apparent KmS of 2 microM for adenine phosphoribosyltransferase and 4 microM for HGPRT, showing two orders of magnitude higher affinities for PRPP than that of the rate-limiting enzyme of de novo purine synthesis, amidophosphoribosyltransferase (EC 2.4.2.14) (Km = 400 to 900 microM)." (6327016)

Regulatory Information

Upstream transcription factor

7428

Regulatory type

Detail

key enzyme;

"The Lesch-Nyhan syndrome is an X-linked disorder caused by a virtually complete absence of the key enzyme of purine recycling, hypoxanthine-guanine phosphoribosyltransferase (HPRT)." (10850548)

others;

"This hysteretic characteristic of AMP pyrophosphorylase may be one of the regulatory mechanisms in purine intermediary metabolism." (1148199)

feedback;

"Studies on inhibition by the reaction product suggest that AMP is a competitive inhibitor with respect to PRPP in both enzymes, with Ki values of 150 microM in Propositus and 220 microM in controlHPRT+." (14674717)

inhibitor;

"Studies on inhibition by the reaction product suggest that AMP is a competitive inhibitor with respect to PRPP in both enzymes, with Ki values of 150 microM in Propositus and 220 microM in controlHPRT+." (14674717)

phosphorylation;

P07741

epigenetic;

"Retention of an elevated CpG dinucleotide content, despite loss of sequence homology, suggests that there may be selection for CpG dinucleotides in these regions and that their maintenance may be important for APRT gene function." (3554238)

interact with TF;VHL(7428)

"Large-scale mapping of human protein-protein interactions by mass spectrometry." (17353931)

Gene ontology

Gene ontology

GO:0006166 (P) purine ribonucleoside salvage [P07741 ];
GO:0003999 (F) adenine phosphoribosyltransferase activity [P07741 ];
GO:0016208 (F) AMP binding [P07741 ];
GO:0006168 (P) adenine salvage [P07741 ];
GO:0005829 (C) cytosol [P07741 ];
GO:0005515 (F) protein binding [P07741 ];

Subcellular localization

Localization

cytoplasm [P07741 ];

Disease relevance

Disease

Defects in APRT are the cause of APRT deficiency [MIM:102600];
also known as 2, 8-dihydroxyadenine urolithiasis. It is an autosomal recessive disease characterized by renal failure. Patients have 2, 8-dihydroxyadenine (DHA) urinary stones [P07741 ];

Links

SwissProt

P07741

Entrez Gene

353

HPRD

00029



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  Last Modified: 2009-03-24  
  Design by Zhao Min