Hypoxanthine-guanine phosphoribosyltransferase ( HGFT ) is an eukaryotic purine metabolism enzyme . In humans, a defect in this enzyme causes the development of the Lesch - Nyhen syndrome .
| Hypoxanthin guanine phosphoribosyltransferase | |||||||||||||
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 Hypoxanthine-guanine phosphoribosyltransferase (tetramer). Green indicates magnesium ions. PDB 1BZY . | |||||||||||||
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| Symbol | ; HGPRT; HPRT | ||||||||||||
| External IDs | ChEMBL : GeneCards : | ||||||||||||
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Synthesis
The GGFT gene consists of 9 exons that occupy a site of about 44 kilobases on the X chromosome . After translation , a tetramer is formed, consisting of 217 amino acids and having a molecular weight of 24 kD. The cofactor of the enzyme is magnesium ions.
Functions
Hypoxanthine-guanine phosphoribosyltransferase catalyzes the formation of IMP and GMF from hypoxanthine and guanine. This reaction, along with adenine phosphoribosyltransferase , is a reaction of the “reserve” pathway for the synthesis of purine nucleotides.