ID   RIHB_ECOHS              Reviewed;         313 AA.
AC   A8A225;
DT   05-FEB-2008, integrated into UniProtKB/Swiss-Prot.
DT   23-OCT-2007, sequence version 1.
DT   03-AUG-2022, entry version 74.
DE   RecName: Full=Pyrimidine-specific ribonucleoside hydrolase RihB {ECO:0000255|HAMAP-Rule:MF_01433};
DE            EC=3.2.2.8 {ECO:0000255|HAMAP-Rule:MF_01433};
DE   AltName: Full=Cytidine/uridine-specific hydrolase {ECO:0000255|HAMAP-Rule:MF_01433};
GN   Name=rihB {ECO:0000255|HAMAP-Rule:MF_01433}; OrderedLocusNames=EcHS_A2298;
OS   Escherichia coli O9:H4 (strain HS).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Escherichia.
OX   NCBI_TaxID=331112;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=HS;
RX   PubMed=18676672; DOI=10.1128/jb.00619-08;
RA   Rasko D.A., Rosovitz M.J., Myers G.S.A., Mongodin E.F., Fricke W.F.,
RA   Gajer P., Crabtree J., Sebaihia M., Thomson N.R., Chaudhuri R.,
RA   Henderson I.R., Sperandio V., Ravel J.;
RT   "The pangenome structure of Escherichia coli: comparative genomic analysis
RT   of E. coli commensal and pathogenic isolates.";
RL   J. Bacteriol. 190:6881-6893(2008).
CC   -!- FUNCTION: Hydrolyzes cytidine or uridine to ribose and cytosine or
CC       uracil, respectively. Has a clear preference for cytidine over uridine.
CC       Strictly specific for ribonucleosides. {ECO:0000255|HAMAP-
CC       Rule:MF_01433}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=a pyrimidine ribonucleoside + H2O = a pyrimidine nucleobase +
CC         D-ribose; Xref=Rhea:RHEA:56816, ChEBI:CHEBI:15377, ChEBI:CHEBI:26432,
CC         ChEBI:CHEBI:47013, ChEBI:CHEBI:141014; EC=3.2.2.8;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01433};
CC   -!- COFACTOR:
CC       Name=Ca(2+); Xref=ChEBI:CHEBI:29108;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01433};
CC       Note=Binds 1 Ca(2+) ion per monomer. {ECO:0000255|HAMAP-Rule:MF_01433};
CC   -!- SUBUNIT: Homotetramer. {ECO:0000255|HAMAP-Rule:MF_01433}.
CC   -!- SIMILARITY: Belongs to the IUNH family. RihB subfamily.
CC       {ECO:0000255|HAMAP-Rule:MF_01433}.
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DR   EMBL; CP000802; ABV06579.1; -; Genomic_DNA.
DR   RefSeq; WP_000415446.1; NC_009800.1.
DR   AlphaFoldDB; A8A225; -.
DR   SMR; A8A225; -.
DR   GeneID; 66673942; -.
DR   KEGG; ecx:EcHS_A2298; -.
DR   HOGENOM; CLU_036838_2_0_6; -.
DR   OMA; REKAHEW; -.
DR   Proteomes; UP000001123; Chromosome.
DR   GO; GO:0005509; F:calcium ion binding; IEA:UniProtKB-UniRule.
DR   GO; GO:0045437; F:uridine nucleosidase activity; IEA:UniProt.
DR   GO; GO:0006206; P:pyrimidine nucleobase metabolic process; IEA:UniProtKB-UniRule.
DR   GO; GO:0046133; P:pyrimidine ribonucleoside catabolic process; IEA:InterPro.
DR   Gene3D; 3.90.245.10; -; 1.
DR   HAMAP; MF_01433; Pyrim_hydro_RihB; 1.
DR   InterPro; IPR015910; I/U_nuclsd_hydro_CS.
DR   InterPro; IPR001910; Inosine/uridine_hydrolase_dom.
DR   InterPro; IPR023186; IUNH.
DR   InterPro; IPR022977; Pyrim_hydro_RihB.
DR   InterPro; IPR036452; Ribo_hydro-like.
DR   PANTHER; PTHR12304; PTHR12304; 1.
DR   Pfam; PF01156; IU_nuc_hydro; 1.
DR   SUPFAM; SSF53590; SSF53590; 1.
DR   PROSITE; PS01247; IUNH; 1.
PE   3: Inferred from homology;
KW   Calcium; Glycosidase; Hydrolase; Metal-binding.
FT   CHAIN           1..313
FT                   /note="Pyrimidine-specific ribonucleoside hydrolase RihB"
FT                   /id="PRO_1000068532"
FT   ACT_SITE        11
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01433"
FT   BINDING         11
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01433"
FT   BINDING         16
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01433"
FT   BINDING         124
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01433"
FT   BINDING         227
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01433"
FT   BINDING         239
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01433"
FT   BINDING         240
FT                   /ligand="Ca(2+)"
FT                   /ligand_id="ChEBI:CHEBI:29108"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01433"
SQ   SEQUENCE   313 AA;  33766 MW;  9D25870C4BEB4AF3 CRC64;
     MEKRKIILDC DPGHDDAIAM MMAAKHPAID LLGITIVAGN QTLDKTLING LNVCQKLEIN
     VPVYAGMPQP IMRKQIVADN IHGETGLDGP VFEPLTRQAE STHAVKYIID TLMASDGDIT
     LVPVGPLSNI AVAMRMQPAI LPKIREIVLM GGAYGTGNFT PSAEFNIFAD PEAARVVFTS
     GVPLVMMGLD LTNQTVCTPD VIARMERAGG PAGELFSDIM NFTLKTQFEN YGLAGGPVHD
     ATCIGYLINP DGIKTQEMYV EVDVNSGPCY GRTVCDELGV LGKPANTKVG ITIDTDWFWG
     LVEECVRGYI KTH