ID   XPT_STRMT               Reviewed;         162 AA.
AC   Q9ZEE3; Q6IUA7; Q9S6U7;
DT   16-AUG-2004, integrated into UniProtKB/Swiss-Prot.
DT   01-MAY-1999, sequence version 1.
DT   03-AUG-2022, entry version 71.
DE   RecName: Full=Xanthine phosphoribosyltransferase;
DE            Short=XPRTase;
DE            EC=2.4.2.22;
DE   Flags: Fragment;
GN   Name=xpt;
OS   Streptococcus mitis.
OC   Bacteria; Firmicutes; Bacilli; Lactobacillales; Streptococcaceae;
OC   Streptococcus.
OX   NCBI_TaxID=28037;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=PN92/120;
RX   PubMed=9846740; DOI=10.1099/00221287-144-11-3049;
RA   Enright M.C., Spratt B.G.;
RT   "A multilocus sequence typing scheme for Streptococcus pneumoniae:
RT   identification of clones associated with serious invasive disease.";
RL   Microbiology 144:3049-3060(1998).
RN   [2] {ECO:0000312|EMBL:AAT45186.1}
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RC   STRAIN=1060;
RA   Leegaard T.M., Caugant D.A., Mansaker T., Froholm L.O., Hoiby E.A.;
RT   "Optochin sensitive, bile-soluble, non-pneumococcal streptococci in HIV-
RT   seropositive patients.";
RL   Submitted (MAY-2004) to the EMBL/GenBank/DDBJ databases.
RN   [3] {ECO:0000305}
RP   NUCLEOTIDE SEQUENCE [GENOMIC DNA] OF 10-140.
RC   STRAIN=ATCC 49456 / DSM 12643 / LMG 14557 / NCTC 12261;
RX   PubMed=10338480; DOI=10.1128/iai.67.6.2776-2782.1999;
RA   Whatmore A.M., King S.J., Doherty N.C., Sturgeon D., Chanter N.,
RA   Dowson C.G.;
RT   "Molecular characterization of equine isolates of Streptococcus pneumoniae:
RT   natural disruption of genes encoding the virulence factors pneumolysin and
RT   autolysin.";
RL   Infect. Immun. 67:2776-2782(1999).
CC   -!- FUNCTION: Converts the preformed base xanthine, a product of nucleic
CC       acid breakdown, to xanthosine 5'-monophosphate (XMP), so it can be
CC       reused for RNA or DNA synthesis. {ECO:0000250}.
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   -!- PATHWAY: Purine metabolism; XMP biosynthesis via salvage pathway; XMP
CC       from xanthine: step 1/1.
CC   -!- SUBUNIT: Homodimer. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Cytoplasm {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the purine/pyrimidine phosphoribosyltransferase
CC       family. Xpt subfamily. {ECO:0000305}.
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DR   EMBL; AJ232400; CAA13403.1; -; Genomic_DNA.
DR   EMBL; AY624671; AAT45186.1; -; Genomic_DNA.
DR   EMBL; AJ240618; CAB39206.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q9ZEE3; -.
DR   SMR; Q9ZEE3; -.
DR   STRING; 585202.SMSK321_1075; -.
DR   UniPathway; UPA00602; UER00658.
DR   GO; GO:0005737; C:cytoplasm; IEA:UniProtKB-SubCell.
DR   GO; GO:0000310; F:xanthine phosphoribosyltransferase activity; IEA:UniProtKB-EC.
DR   GO; GO:0006166; P:purine ribonucleoside salvage; IEA:UniProtKB-KW.
DR   GO; GO:0046110; P:xanthine metabolic process; IEA:InterPro.
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; IPR000836; PRibTrfase_dom.
DR   InterPro; IPR029057; PRTase-like.
DR   InterPro; IPR010079; Xanthine_PRibTrfase.
DR   Pfam; PF00156; Pribosyltran; 1.
DR   SUPFAM; SSF53271; SSF53271; 1.
DR   TIGRFAMs; TIGR01744; XPRTase; 1.
PE   3: Inferred from homology;
KW   Cytoplasm; Glycosyltransferase; Purine salvage; Transferase.
FT   CHAIN           <1..>162
FT                   /note="Xanthine phosphoribosyltransferase"
FT                   /id="PRO_0000139698"
FT   BINDING         5
FT                   /ligand="xanthine"
FT                   /ligand_id="ChEBI:CHEBI:17712"
FT                   /evidence="ECO:0000250"
FT   BINDING         12
FT                   /ligand="xanthine"
FT                   /ligand_id="ChEBI:CHEBI:17712"
FT                   /evidence="ECO:0000250"
FT   BINDING         113..117
FT                   /ligand="5-phospho-alpha-D-ribose 1-diphosphate"
FT                   /ligand_id="ChEBI:CHEBI:58017"
FT                   /evidence="ECO:0000250"
FT   BINDING         141
FT                   /ligand="xanthine"
FT                   /ligand_id="ChEBI:CHEBI:17712"
FT                   /evidence="ECO:0000250"
FT   VARIANT         29
FT                   /note="E -> D (in strain: 12261)"
FT                   /evidence="ECO:0000305"
FT   VARIANT         51
FT                   /note="V -> I (in strain: 12261)"
FT                   /evidence="ECO:0000305"
FT   VARIANT         58
FT                   /note="N -> D (in strain: 12261)"
FT                   /evidence="ECO:0000305"
FT   VARIANT         131
FT                   /note="T -> K (in strain: 12261)"
FT                   /evidence="ECO:0000305"
FT   NON_TER         1
FT                   /evidence="ECO:0000305"
FT   NON_TER         162
FT                   /evidence="ECO:0000305"
SQ   SEQUENCE   162 AA;  17320 MW;  FD8FC18539BEE3E5 CRC64;
     GDNILKVDSF LTHQVDFSLM REIGKVFAEK FASAGITKVV TIEASGIAPA VFTAEALNVP
     MIFAKKAKNI TMNEGILTAQ VYSFTKQVTS TVSIAGKFLS PEDKVLIIDD FLANGQAAKG
     LIQIIEQAGA TVEAIGIVIE KSFQDGRDLL EKAGYPVLSL AR