ID   TENA_STAA3              Reviewed;         229 AA.
AC   Q2FF32;
DT   10-JUL-2007, integrated into UniProtKB/Swiss-Prot.
DT   21-MAR-2006, sequence version 1.
DT   03-AUG-2022, entry version 79.
DE   RecName: Full=Aminopyrimidine aminohydrolase {ECO:0000250|UniProtKB:P25052};
DE            EC=3.5.99.2 {ECO:0000250|UniProtKB:Q6GEY1};
DE   AltName: Full=Thiaminase II {ECO:0000250|UniProtKB:Q6GEY1};
GN   Name=tenA; OrderedLocusNames=SAUSA300_2050;
OS   Staphylococcus aureus (strain USA300).
OC   Bacteria; Firmicutes; Bacilli; Bacillales; Staphylococcaceae;
OC   Staphylococcus.
OX   NCBI_TaxID=367830;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=USA300;
RX   PubMed=16517273; DOI=10.1016/s0140-6736(06)68231-7;
RA   Diep B.A., Gill S.R., Chang R.F., Phan T.H., Chen J.H., Davidson M.G.,
RA   Lin F., Lin J., Carleton H.A., Mongodin E.F., Sensabaugh G.F.,
RA   Perdreau-Remington F.;
RT   "Complete genome sequence of USA300, an epidemic clone of community-
RT   acquired meticillin-resistant Staphylococcus aureus.";
RL   Lancet 367:731-739(2006).
CC   -!- FUNCTION: Catalyzes an amino-pyrimidine hydrolysis reaction at the C5'
CC       of the pyrimidine moiety of thiamine compounds, a reaction that is part
CC       of a thiamine salvage pathway. Thus, catalyzes the conversion of 4-
CC       amino-5-aminomethyl-2-methylpyrimidine to 4-amino-5-hydroxymethyl-2-
CC       methylpyrimidine (HMP). Is also able to catalyze the hydrolytic
CC       cleavage of thiamine; however, this thiaminase activity may not be
CC       physiologically relevant. Therefore, is probably involved in the
CC       regeneration of the thiamine pyrimidine from thiamine degraded products
CC       present in the environment, rather than in thiamine degradation.
CC       {ECO:0000250|UniProtKB:P25052, ECO:0000250|UniProtKB:Q6GEY1}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=4-amino-5-aminomethyl-2-methylpyrimidine + H2O = 4-amino-5-
CC         hydroxymethyl-2-methylpyrimidine + NH4(+); Xref=Rhea:RHEA:31799,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:16892, ChEBI:CHEBI:28938,
CC         ChEBI:CHEBI:63416; EC=3.5.99.2;
CC         Evidence={ECO:0000250|UniProtKB:P25052};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=H2O + thiamine = 4-amino-5-hydroxymethyl-2-methylpyrimidine +
CC         5-(2-hydroxyethyl)-4-methylthiazole + H(+); Xref=Rhea:RHEA:17509,
CC         ChEBI:CHEBI:15377, ChEBI:CHEBI:15378, ChEBI:CHEBI:16892,
CC         ChEBI:CHEBI:17957, ChEBI:CHEBI:18385; EC=3.5.99.2;
CC         Evidence={ECO:0000250|UniProtKB:Q6GEY1};
CC   -!- PATHWAY: Cofactor biosynthesis; thiamine diphosphate biosynthesis.
CC       {ECO:0000250|UniProtKB:P25052}.
CC   -!- SUBUNIT: Homotetramer. {ECO:0000250|UniProtKB:Q6GEY1}.
CC   -!- SIMILARITY: Belongs to the TenA family. {ECO:0000305}.
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DR   EMBL; CP000255; ABD22120.1; -; Genomic_DNA.
DR   RefSeq; WP_000396077.1; NZ_CP027476.1.
DR   AlphaFoldDB; Q2FF32; -.
DR   SMR; Q2FF32; -.
DR   EnsemblBacteria; ABD22120; ABD22120; SAUSA300_2050.
DR   KEGG; saa:SAUSA300_2050; -.
DR   HOGENOM; CLU_077537_3_1_9; -.
DR   OMA; SAHHYIR; -.
DR   UniPathway; UPA00060; -.
DR   Proteomes; UP000001939; Chromosome.
DR   GO; GO:0050334; F:thiaminase activity; IEA:UniProtKB-EC.
DR   GO; GO:0009228; P:thiamine biosynthetic process; IEA:UniProtKB-KW.
DR   GO; GO:0009229; P:thiamine diphosphate biosynthetic process; IEA:UniProtKB-UniPathway.
DR   Gene3D; 1.20.910.10; -; 1.
DR   InterPro; IPR016084; Haem_Oase-like_multi-hlx.
DR   InterPro; IPR004305; Thiaminase-2/PQQC.
DR   InterPro; IPR027574; Thiaminase_II.
DR   Pfam; PF03070; TENA_THI-4; 1.
DR   SUPFAM; SSF48613; SSF48613; 1.
DR   TIGRFAMs; TIGR04306; salvage_TenA; 1.
PE   3: Inferred from homology;
KW   Hydrolase; Thiamine biosynthesis.
FT   CHAIN           1..229
FT                   /note="Aminopyrimidine aminohydrolase"
FT                   /id="PRO_0000293613"
FT   ACT_SITE        137
FT                   /note="Nucleophile"
FT                   /evidence="ECO:0000250|UniProtKB:P25052"
FT   ACT_SITE        208
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000250|UniProtKB:P25052"
FT   BINDING         44
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P25052"
FT   BINDING         141
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P25052"
FT   BINDING         167
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000250|UniProtKB:P25052"
FT   SITE            47
FT                   /note="Increases nucleophilicity of active site Cys"
FT                   /evidence="ECO:0000250|UniProtKB:P25052"
SQ   SEQUENCE   229 AA;  26729 MW;  3D013A7D04082701 CRC64;
     MEFSQKLYQA AKPIINDIYE DDFIQKMLSG DIGADALRHY LKADAAYLKE FTNLYALLIP
     KMNSMNDVKF LVEQIEFMVE GEVLAHDILA QIVGESYEEI IKTKVWPPSG DHYIKHMYFQ
     AHSRENAIYT IAAMAPCPYI YAELAKRSQS DHKLNREKDT AKWFDFYSTE MDDIINVFEA
     LMNKLAESMS DKELEQVKQV FLESCIHERR FFNMAMTLEQ WEFGGKVND