hypoxanthine phosphoribosyltransferase 1(HPRT1) Homo sapiens The protein encoded by this gene is a transferase, which catalyzes conversion of hypoxanthine to inosine monophosphate and guanine to guanosine monophosphate via transfer of the 5-phosphoribosyl group from 5-phosphoribosyl 1-pyrophosphate. This enzyme plays a central role in the generation of purine nucleotides through the purine salvage pathway. Mutations in this gene result in Lesch-Nyhan syndrome or gout.[provided by RefSeq, Jun 2009],
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Function:
Catalytic activity:GMP + diphosphate = guanine + 5-phospho-alpha-D-ribose 1-diphosphate.,Catalytic activity:IMP + diphosphate = hypoxanthine + 5-phospho-alpha-D-ribose 1-diphosphate.,cofactor:Binds 2 magnesium ions per subunit. One of the ions does not make direct protein contacts.,Disease:Defects in HPRT1 are the cause of gout [MIM:300323]; also known as HPRT-related gout or Kelley-Seegmiller syndrome. Gout is characterized by partial enzyme activity and hyperuricemia.,Disease:Defects in HPRT1 are the cause of Lesch-Nyhan syndrome (LNS) [MIM:300322]. LNS is characterized by complete lack of enzymatic activity that results in hyperuricemia, choreoathetosis, mental retardation, and compulsive self-mutilation.,online information:Hypoxanthine-guanine phosphoribosyltransferase entry,pathway:Purine metabolism; IMP biosynthesis via salvage pathway; IMP from hypoxanthine: step 1/1.,similarity:Belongs to the purine/pyrimidine phosphoribosyltransferase family.,subunit:Homotetramer.,