LMPD Database

LMP006999

UniProt Annotations

Entry Information
Gene Namehypoxanthine phosphoribosyltransferase
Protein EntryHPRT_YEAST
UniProt IDQ04178
SpeciesYeast (S288c)
Comments
Comment typeDescription
Biophysicochemical PropertiesKinetic parameters: KM=23 uM for hypoxanthine {ECO:0000269|PubMed:371963, ECO:0000269|PubMed:6170313, ECO:0000269|PubMed:7035445}; KM=18 uM for guanine {ECO:0000269|PubMed:371963, ECO:0000269|PubMed:6170313, ECO:0000269|PubMed:7035445}; KM=50 uM for phosphoribosylpyrophosphate {ECO:0000269|PubMed:371963, ECO:0000269|PubMed:6170313, ECO:0000269|PubMed:7035445}; pH dependence: Optimum pH is 8.5. {ECO:0000269|PubMed:371963, ECO:0000269|PubMed:6170313, ECO:0000269|PubMed:7035445};
Catalytic ActivityGMP + diphosphate = guanine + 5-phospho-alpha- D-ribose 1-diphosphate. {ECO:0000269|PubMed:18245832}.
Catalytic ActivityIMP + diphosphate = hypoxanthine + 5-phospho- alpha-D-ribose 1-diphosphate. {ECO:0000269|PubMed:18245832}.
CofactorName=Mg(2+); Xref=ChEBI:CHEBI:18420; Note=The magnesium ions are essentially bound to the substrate and have few direct interactions with the protein.;
Enzyme RegulationSubject to feedback inhibition by GMP. {ECO:0000269|PubMed:18245832}.
FunctionConverts guanine to guanosine monophosphate, and hypoxanthine to inosine monophosphate. Transfers the 5- phosphoribosyl group from 5-phosphoribosylpyrophosphate onto the purine. Plays a central role in the generation of purine nucleotides through the purine salvage pathway. {ECO:0000269|PubMed:11035032, ECO:0000269|PubMed:18245832, ECO:0000269|PubMed:371963, ECO:0000269|PubMed:6170313, ECO:0000269|PubMed:6392474, ECO:0000269|PubMed:7035445, ECO:0000269|PubMed:9335580}.
MiscellaneousPresent with 36500 molecules/cell in log phase SD medium. {ECO:0000269|PubMed:14562106}.
PathwayPurine metabolism; IMP biosynthesis via salvage pathway; IMP from hypoxanthine: step 1/1.
SimilarityBelongs to the purine/pyrimidine phosphoribosyltransferase family. {ECO:0000305}.
Subcellular LocationCytoplasm {ECO:0000269|PubMed:14562095}. Nucleus {ECO:0000269|PubMed:14562095}.
SubunitDimer. {ECO:0000269|PubMed:18245832, ECO:0000269|PubMed:6170313}.