ID   MTIP_METKA              Reviewed;         256 AA.
AC   Q8TZB4;
DT   25-JAN-2012, integrated into UniProtKB/Swiss-Prot.
DT   01-JUN-2002, sequence version 1.
DT   03-AUG-2022, entry version 82.
DE   RecName: Full=Probable S-methyl-5'-thioinosine phosphorylase {ECO:0000255|HAMAP-Rule:MF_01963};
DE            EC=2.4.2.44 {ECO:0000255|HAMAP-Rule:MF_01963};
DE   AltName: Full=5'-methylthioinosine phosphorylase {ECO:0000255|HAMAP-Rule:MF_01963};
DE            Short=MTI phosphorylase {ECO:0000255|HAMAP-Rule:MF_01963};
DE            Short=MTIP {ECO:0000255|HAMAP-Rule:MF_01963};
GN   OrderedLocusNames=MK0021;
OS   Methanopyrus kandleri (strain AV19 / DSM 6324 / JCM 9639 / NBRC 100938).
OC   Archaea; Euryarchaeota; Methanopyri; Methanopyrales; Methanopyraceae;
OC   Methanopyrus.
OX   NCBI_TaxID=190192;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=AV19 / DSM 6324 / JCM 9639 / NBRC 100938;
RX   PubMed=11930014; DOI=10.1073/pnas.032671499;
RA   Slesarev A.I., Mezhevaya K.V., Makarova K.S., Polushin N.N.,
RA   Shcherbinina O.V., Shakhova V.V., Belova G.I., Aravind L., Natale D.A.,
RA   Rogozin I.B., Tatusov R.L., Wolf Y.I., Stetter K.O., Malykh A.G.,
RA   Koonin E.V., Kozyavkin S.A.;
RT   "The complete genome of hyperthermophile Methanopyrus kandleri AV19 and
RT   monophyly of archaeal methanogens.";
RL   Proc. Natl. Acad. Sci. U.S.A. 99:4644-4649(2002).
CC   -!- FUNCTION: Catalyzes the reversible phosphorylation of S-methyl-5'-
CC       thioinosine (MTI) to hypoxanthine and 5-methylthioribose-1-phosphate.
CC       Involved in the breakdown of S-methyl-5'-thioadenosine (MTA), a major
CC       by-product of polyamine biosynthesis. Catabolism of (MTA) occurs via
CC       deamination to MTI and phosphorolysis to hypoxanthine.
CC       {ECO:0000255|HAMAP-Rule:MF_01963}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=phosphate + S-methyl-5'-thioinosine = hypoxanthine + S-methyl-
CC         5-thio-alpha-D-ribose 1-phosphate; Xref=Rhea:RHEA:30643,
CC         ChEBI:CHEBI:17368, ChEBI:CHEBI:43474, ChEBI:CHEBI:48595,
CC         ChEBI:CHEBI:58533; EC=2.4.2.44; Evidence={ECO:0000255|HAMAP-
CC         Rule:MF_01963};
CC   -!- PATHWAY: Purine metabolism; purine nucleoside salvage.
CC       {ECO:0000255|HAMAP-Rule:MF_01963}.
CC   -!- SUBUNIT: Homotrimer. {ECO:0000255|HAMAP-Rule:MF_01963}.
CC   -!- MISCELLANEOUS: Although this enzyme belongs to the family of MTA
CC       phosphorylases based on sequence homology, it has been shown that
CC       conserved amino acid substitutions in the substrate binding pocket
CC       convert the substrate specificity of this enzyme from 6-aminopurines to
CC       6-oxopurines. {ECO:0000255|HAMAP-Rule:MF_01963}.
CC   -!- SIMILARITY: Belongs to the PNP/MTAP phosphorylase family. MTAP
CC       subfamily. {ECO:0000255|HAMAP-Rule:MF_01963}.
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DR   EMBL; AE009439; AAM01238.1; -; Genomic_DNA.
DR   AlphaFoldDB; Q8TZB4; -.
DR   SMR; Q8TZB4; -.
DR   STRING; 190192.MK0021; -.
DR   EnsemblBacteria; AAM01238; AAM01238; MK0021.
DR   KEGG; mka:MK0021; -.
DR   PATRIC; fig|190192.8.peg.21; -.
DR   HOGENOM; CLU_054456_0_2_2; -.
DR   OMA; MTQCPEA; -.
DR   UniPathway; UPA00606; -.
DR   Proteomes; UP000001826; Chromosome.
DR   GO; GO:0017061; F:S-methyl-5-thioadenosine phosphorylase activity; IEA:InterPro.
DR   GO; GO:0006166; P:purine ribonucleoside salvage; IEA:UniProtKB-UniRule.
DR   CDD; cd09010; MTAP_SsMTAPII_like_MTIP; 1.
DR   Gene3D; 3.40.50.1580; -; 1.
DR   HAMAP; MF_01963; MTAP; 1.
DR   InterPro; IPR010044; MTAP.
DR   InterPro; IPR000845; Nucleoside_phosphorylase_d.
DR   InterPro; IPR035994; Nucleoside_phosphorylase_sf.
DR   PANTHER; PTHR42679; PTHR42679; 1.
DR   Pfam; PF01048; PNP_UDP_1; 1.
DR   SUPFAM; SSF53167; SSF53167; 1.
DR   TIGRFAMs; TIGR01694; MTAP; 1.
PE   3: Inferred from homology;
KW   Glycosyltransferase; Purine salvage; Reference proteome; Transferase.
FT   CHAIN           1..256
FT                   /note="Probable S-methyl-5'-thioinosine phosphorylase"
FT                   /id="PRO_0000415142"
FT   BINDING         10
FT                   /ligand="phosphate"
FT                   /ligand_id="ChEBI:CHEBI:43474"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01963"
FT   BINDING         47..48
FT                   /ligand="phosphate"
FT                   /ligand_id="ChEBI:CHEBI:43474"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01963"
FT   BINDING         178
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01963"
FT   BINDING         179
FT                   /ligand="phosphate"
FT                   /ligand_id="ChEBI:CHEBI:43474"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01963"
FT   BINDING         202..204
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01963"
FT   SITE            160
FT                   /note="Important for substrate specificity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01963"
FT   SITE            214
FT                   /note="Important for substrate specificity"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01963"
SQ   SEQUENCE   256 AA;  28790 MW;  C3DD32D388C8D4ED CRC64;
     MTEVGVIGGT GFQPGLPERR RTVFTPYGTV RVDITRVGDH RVYFINRHGK GHDLPPHRIN
     YRAIVWAMRE LGVKRILATN SVGVINSDEY EPGDIVLPVD FLDFTKRRPT TFYDEKVVHV
     DVTEPYCPEL REALLKAADD LGYTVKEGAV YVATEGPRFE TPAEIRAFRK LGGDIVGMTG
     FPEVVLAREL EICYASVCLC TNYAAGIDDR RRTIDEVFEL VEELRPKAVE LIERCIEYIP
     PKRSCPCSQA LEGAEV