ID   HPRT_CRIFA              Reviewed;         208 AA.
AC   Q27541;
DT   06-DEC-2002, integrated into UniProtKB/Swiss-Prot.
DT   01-NOV-1996, sequence version 1.
DT   13-SEP-2023, entry version 82.
DE   RecName: Full=Hypoxanthine-guanine phosphoribosyltransferase;
DE            Short=HGPRT;
DE            Short=HGPRTase;
DE            EC=2.4.2.8;
GN   Name=HGPRT;
OS   Crithidia fasciculata.
OC   Eukaryota; Discoba; Euglenozoa; Kinetoplastea; Metakinetoplastina;
OC   Trypanosomatida; Trypanosomatidae; Leishmaniinae; Crithidia.
OX   NCBI_TaxID=5656;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX   PubMed=8617334; DOI=10.1006/expr.1996.0010;
RA   Jiang Y., Allen T.E., Carter D., Ray D.S., Ullman B.;
RT   "Crithidia fasciculata: isolation, sequencing, and expression of the
RT   hypoxanthine-guanine phosphoribosyltransferase gene.";
RL   Exp. Parasitol. 82:73-75(1996).
CC   -!- FUNCTION: Converts guanine to guanosine monophosphate, and hypoxanthine
CC       to inosine monophosphate. Transfers the 5-phosphoribosyl group from 5-
CC       phosphoribosylpyrophosphate onto the purine. Plays a central role in
CC       the generation of purine nucleotides through the purine salvage pathway
CC       (By similarity). {ECO:0000250}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=diphosphate + IMP = 5-phospho-alpha-D-ribose 1-diphosphate +
CC         hypoxanthine; Xref=Rhea:RHEA:17973, ChEBI:CHEBI:17368,
CC         ChEBI:CHEBI:33019, ChEBI:CHEBI:58017, ChEBI:CHEBI:58053; EC=2.4.2.8;
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=diphosphate + GMP = 5-phospho-alpha-D-ribose 1-diphosphate +
CC         guanine; Xref=Rhea:RHEA:25424, ChEBI:CHEBI:16235, ChEBI:CHEBI:33019,
CC         ChEBI:CHEBI:58017, ChEBI:CHEBI:58115; EC=2.4.2.8;
CC   -!- COFACTOR:
CC       Name=Mg(2+); Xref=ChEBI:CHEBI:18420; Evidence={ECO:0000250};
CC       Note=Binds 2 magnesium ions per subunit. The magnesium ions are
CC       essentially bound to the substrate and have few direct interactions
CC       with the protein. {ECO:0000250};
CC   -!- PATHWAY: Purine metabolism; IMP biosynthesis via salvage pathway; IMP
CC       from hypoxanthine: step 1/1.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm.
CC   -!- SIMILARITY: Belongs to the purine/pyrimidine phosphoribosyltransferase
CC       family. {ECO:0000305}.
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DR   EMBL; U19968; AAB04164.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q27541; -.
DR   SMR; Q27541; -.
DR   VEuPathDB; TriTrypDB:CFAC1_130013300; -.
DR   UniPathway; UPA00591; UER00648.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0052657; F:guanine phosphoribosyltransferase activity; IEA:UniProtKB-EC.
DR   GO; GO:0004422; F:hypoxanthine phosphoribosyltransferase activity; IEA:UniProtKB-EC.
DR   GO; GO:0046872; F:metal ion binding; IEA:UniProtKB-KW.
DR   GO; GO:0000166; F:nucleotide binding; IEA:UniProtKB-KW.
DR   GO; GO:0032264; P:IMP salvage; IEA:UniProtKB-UniPathway.
DR   GO; GO:0006166; P:purine ribonucleoside salvage; IEA:UniProtKB-KW.
DR   CDD; cd06223; PRTases_typeI; 1.
DR   Gene3D; 3.40.50.2020; -; 1.
DR   InterPro; IPR005904; Hxn_phspho_trans.
DR   InterPro; IPR000836; PRibTrfase_dom.
DR   InterPro; IPR029057; PRTase-like.
DR   NCBIfam; TIGR01203; HGPRTase; 1.
DR   PANTHER; PTHR43340:SF1; HYPOXANTHINE PHOSPHORIBOSYLTRANSFERASE; 1.
DR   PANTHER; PTHR43340; HYPOXANTHINE-GUANINE PHOSPHORIBOSYLTRANSFERASE; 1.
DR   Pfam; PF00156; Pribosyltran; 1.
DR   SUPFAM; SSF53271; PRTase-like; 1.
DR   PROSITE; PS00103; PUR_PYR_PR_TRANSFER; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; Glycosyltransferase; Magnesium; Metal-binding;
KW   Nucleotide-binding; Purine salvage; Transferase.
FT   CHAIN           1..208
FT                   /note="Hypoxanthine-guanine phosphoribosyltransferase"
FT                   /id="PRO_0000139595"
FT   ACT_SITE        126
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000250"
FT   BINDING         63
FT                   /ligand="GMP"
FT                   /ligand_id="ChEBI:CHEBI:58115"
FT                   /evidence="ECO:0000250"
FT   BINDING         122..130
FT                   /ligand="GMP"
FT                   /ligand_id="ChEBI:CHEBI:58115"
FT                   /evidence="ECO:0000250"
FT   BINDING         154
FT                   /ligand="GMP"
FT                   /ligand_id="ChEBI:CHEBI:58115"
FT                   /evidence="ECO:0000250"
FT   BINDING         182
FT                   /ligand="GMP"
FT                   /ligand_id="ChEBI:CHEBI:58115"
FT                   /evidence="ECO:0000250"
FT   BINDING         182
FT                   /ligand="Mg(2+)"
FT                   /ligand_id="ChEBI:CHEBI:18420"
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   208 AA;  23323 MW;  7205B52781372EE1 CRC64;
     MSNAASPATS AAPVRHYPMS CRTLATQEQI WSATAKCAKQ IAEDYKQYNL SDENPLYLLC
     VLKGSFMFTA DLARFLCDEG VPVRIEFICA SSYGTDVKTS GEVRLLLDVR DPVENRHLLI
     VEDIVDSAIT LEYLKRFLQA KQPASLKTVV LLDKPSGRKV TLSVDYPVIT IPHAFVIGYG
     MDFAEAYREL RDVCVLKKEY YEKPASKL
//