HGXR_TRIFO
ID HGXR_TRIFO Reviewed; 183 AA.
AC P51900;
DT 01-OCT-1996, integrated into UniProtKB/Swiss-Prot.
DT 01-OCT-1996, sequence version 1.
DT 03-AUG-2022, entry version 97.
DE RecName: Full=Hypoxanthine-guanine-xanthine phosphoribosyltransferase;
DE Short=HGPRT;
DE Short=HGXPRT;
DE Short=HGXPRTase;
DE EC=2.4.2.22 {ECO:0000250|UniProtKB:Q26997};
DE EC=2.4.2.8 {ECO:0000250|UniProtKB:Q26997};
GN Name=HPT;
OS Tritrichomonas foetus (Trichomonas foetus) (Tritrichomonas suis).
OC Eukaryota; Metamonada; Parabasalia; Tritrichomonadida; Tritrichomonadidae;
OC Tritrichomonas.
OX NCBI_TaxID=56690;
RN [1]
RP NUCLEOTIDE SEQUENCE.
RC STRAIN=KV1;
RX PubMed=8008020; DOI=10.1016/0166-6851(94)90058-2;
RA Chin M.S., Wang C.C.;
RT "Isolation, sequencing and expression of the gene encoding hypoxanthine-
RT guanine-xanthine phosphoribosyltransferase of Tritrichomonas foetus.";
RL Mol. Biochem. Parasitol. 63:221-229(1994).
RN [2]
RP X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS), AND MASS SPECTROMETRY.
RX PubMed=8679528; DOI=10.1021/bi953072p;
RA Somoza J.R., Chin M.S., Focia P.J., Wang C.C., Fletterick R.J.;
RT "Crystal structure of the hypoxanthine-guanine-xanthine
RT phosphoribosyltransferase from the protozoan parasite Tritrichomonas
RT foetus.";
RL Biochemistry 35:7032-7040(1996).
RN [3]
RP COVALENT MODIFICATION OF CYSTEINES.
RX PubMed=8774725; DOI=10.1111/j.1432-1033.1996.0764u.x;
RA Kanaani J., Somoza J.R., Maltby D., Wang C.C.;
RT "Probing the active site of Tritrichomonas foetus hypoxanthine-guanine-
RT xanthine phosphoribosyltransferase using covalent modification of cysteine
RT residues.";
RL Eur. J. Biochem. 239:764-772(1996).
CC -!- FUNCTION: Essential in nucleic acid metabolism of T.foetus because the
CC parasite is unable to synthesize purine nucleotides de novo and relies
CC on the HGXPRTase activities for its purine requirements by salvaging
CC purine bases from the host. Works with guanine, hypoxanthine and
CC xanthine.
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 Evidence={ECO:0000250|UniProtKB:Q26997};
CC PhysiologicalDirection=right-to-left; Xref=Rhea:RHEA:17975;
CC Evidence={ECO:0000250|UniProtKB:Q26997};
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 Evidence={ECO:0000250|UniProtKB:Q26997};
CC PhysiologicalDirection=right-to-left; Xref=Rhea:RHEA:25426;
CC Evidence={ECO:0000250|UniProtKB:Q26997};
CC -!- CATALYTIC ACTIVITY:
CC Reaction=diphosphate + XMP = 5-phospho-alpha-D-ribose 1-diphosphate +
CC xanthine; Xref=Rhea:RHEA:10800, ChEBI:CHEBI:17712, ChEBI:CHEBI:33019,
CC ChEBI:CHEBI:57464, ChEBI:CHEBI:58017; EC=2.4.2.22;
CC Evidence={ECO:0000250|UniProtKB:Q26997};
CC PhysiologicalDirection=right-to-left; Xref=Rhea:RHEA:10802;
CC Evidence={ECO:0000250|UniProtKB:Q26997};
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; GMP biosynthesis via salvage pathway; GMP
CC from guanine: step 1/1.
CC -!- PATHWAY: Purine metabolism; IMP biosynthesis via salvage pathway; IMP
CC from hypoxanthine: step 1/1.
CC -!- PATHWAY: Purine metabolism; XMP biosynthesis via salvage pathway; XMP
CC from xanthine: step 1/1.
CC -!- SUBUNIT: Homodimer.
CC -!- SUBCELLULAR LOCATION: Cytoplasm.
CC -!- MASS SPECTROMETRY: Mass=21091.04; Mass_error=1.48; Method=Electrospray;
CC Evidence={ECO:0000269|PubMed:8679528};
CC -!- SIMILARITY: Belongs to the purine/pyrimidine phosphoribosyltransferase
CC family. {ECO:0000305}.
CC ---------------------------------------------------------------------------
CC Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC ---------------------------------------------------------------------------
DR EMBL; L08622; AAC37202.1; -; Unassigned_DNA.
DR PDB; 1HGX; X-ray; 1.90 A; A/B=1-183.
DR PDBsum; 1HGX; -.
DR AlphaFoldDB; P51900; -.
DR SMR; P51900; -.
DR VEuPathDB; TrichDB:TRFO_03136; -.
DR SABIO-RK; P51900; -.
DR UniPathway; UPA00591; UER00648.
DR UniPathway; UPA00602; UER00658.
DR UniPathway; UPA00909; UER00887.
DR EvolutionaryTrace; P51900; -.
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:0000310; F:xanthine phosphoribosyltransferase activity; IEA:UniProtKB-EC.
DR GO; GO:0032263; P:GMP salvage; IEA:UniProtKB-UniPathway.
DR GO; GO:0032264; P:IMP salvage; IEA:UniProtKB-UniPathway.
DR GO; GO:0006166; P:purine ribonucleoside salvage; IEA:UniProtKB-KW.
DR GO; GO:0032265; P:XMP salvage; IEA:UniProtKB-UniPathway.
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 Pfam; PF00156; Pribosyltran; 1.
DR SUPFAM; SSF53271; SSF53271; 1.
DR TIGRFAMs; TIGR01203; HGPRTase; 1.
DR PROSITE; PS00103; PUR_PYR_PR_TRANSFER; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Cytoplasm; Glycosyltransferase; Magnesium; Metal-binding;
KW Nucleotide-binding; Purine salvage; Transferase.
FT CHAIN 1..183
FT /note="Hypoxanthine-guanine-xanthine
FT phosphoribosyltransferase"
FT /id="PRO_0000139600"
FT ACT_SITE 106
FT /note="Proton acceptor"
FT /evidence="ECO:0000250"
FT BINDING 102..110
FT /ligand="GMP"
FT /ligand_id="ChEBI:CHEBI:58115"
FT BINDING 134
FT /ligand="GMP"
FT /ligand_id="ChEBI:CHEBI:58115"
FT BINDING 163
FT /ligand="GMP"
FT /ligand_id="ChEBI:CHEBI:58115"
FT BINDING 163
FT /ligand="Mg(2+)"
FT /ligand_id="ChEBI:CHEBI:18420"
FT /evidence="ECO:0000250"
FT STRAND 10..15
FT /evidence="ECO:0007829|PDB:1HGX"
FT HELIX 17..35
FT /evidence="ECO:0007829|PDB:1HGX"
FT TURN 36..38
FT /evidence="ECO:0007829|PDB:1HGX"
FT STRAND 41..45
FT /evidence="ECO:0007829|PDB:1HGX"
FT TURN 46..49
FT /evidence="ECO:0007829|PDB:1HGX"
FT HELIX 50..57
FT /evidence="ECO:0007829|PDB:1HGX"
FT STRAND 65..72
FT /evidence="ECO:0007829|PDB:1HGX"
FT STRAND 84..87
FT /evidence="ECO:0007829|PDB:1HGX"
FT STRAND 96..108
FT /evidence="ECO:0007829|PDB:1HGX"
FT HELIX 109..119
FT /evidence="ECO:0007829|PDB:1HGX"
FT STRAND 124..134
FT /evidence="ECO:0007829|PDB:1HGX"
FT STRAND 146..152
FT /evidence="ECO:0007829|PDB:1HGX"
FT STRAND 157..159
FT /evidence="ECO:0007829|PDB:1HGX"
FT STRAND 172..177
FT /evidence="ECO:0007829|PDB:1HGX"
SQ SEQUENCE 183 AA; 21091 MW; A151E2F5D7D1C214 CRC64;
MTETPMMDDL ERVLYNQDDI QKRIRELAAE LTEFYEDKNP VMICVLTGAV FFYTDLLKHL
DFQLEPDYII CSSYSGTKST GNLTISKDLK TNIEGRHVLV VEDIIDTGLT MYQLLNNLQM
RKPASLKVCT LCDKDIGKKA YDVPIDYCGF VVENRYIIGY GFDFHNKYRN LPVIGILKES
VYT
