ID   MTNN_CROS8              Reviewed;         232 AA.
AC   A7MGS5;
DT   20-JAN-2009, integrated into UniProtKB/Swiss-Prot.
DT   02-OCT-2007, sequence version 1.
DT   04-NOV-2026, entry version 96.
DE   RecName: Full=5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE            Short=MTA/SAH nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE            Short=MTAN {ECO:0000255|HAMAP-Rule:MF_01684};
DE            EC=3.2.2.9 {ECO:0000255|HAMAP-Rule:MF_01684};
DE   AltName: Full=5'-deoxyadenosine nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE            Short=DOA nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE            Short=dAdo nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE   AltName: Full=5'-methylthioadenosine nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE            Short=MTA nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE   AltName: Full=S-adenosylhomocysteine nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE            Short=AdoHcy nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE            Short=SAH nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
DE            Short=SRH nucleosidase {ECO:0000255|HAMAP-Rule:MF_01684};
GN   Name=mtnN {ECO:0000255|HAMAP-Rule:MF_01684};
GN   OrderedLocusNames=ESA_03181;
OS   Cronobacter sakazakii (strain ATCC BAA-894) (Enterobacter sakazakii).
OC   Bacteria; Pseudomonadati; Pseudomonadota; Gammaproteobacteria;
OC   Enterobacterales; Enterobacteriaceae; Cronobacter.
OX   NCBI_TaxID=290339;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=ATCC BAA-894;
RX   PubMed=20221447; DOI=10.1371/journal.pone.0009556;
RA   Kucerova E., Clifton S.W., Xia X.Q., Long F., Porwollik S., Fulton L.,
RA   Fronick C., Minx P., Kyung K., Warren W., Fulton R., Feng D., Wollam A.,
RA   Shah N., Bhonagiri V., Nash W.E., Hallsworth-Pepin K., Wilson R.K.,
RA   McClelland M., Forsythe S.J.;
RT   "Genome sequence of Cronobacter sakazakii BAA-894 and comparative genomic
RT   hybridization analysis with other Cronobacter species.";
RL   PLoS ONE 5:E9556-E9556(2010).
CC   -!- FUNCTION: Catalyzes the irreversible cleavage of the glycosidic bond in
CC       both 5'-methylthioadenosine (MTA) and S-adenosylhomocysteine
CC       (SAH/AdoHcy) to adenine and the corresponding thioribose, 5'-
CC       methylthioribose and S-ribosylhomocysteine, respectively. Also cleaves
CC       5'-deoxyadenosine, a toxic by-product of radical S-adenosylmethionine
CC       (SAM) enzymes, into 5-deoxyribose and adenine. Thus, is required for in
CC       vivo function of the radical SAM enzymes biotin synthase and lipoic
CC       acid synthase, that are inhibited by 5'-deoxyadenosine accumulation.
CC       {ECO:0000255|HAMAP-Rule:MF_01684}.
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=S-adenosyl-L-homocysteine + H2O = S-(5-deoxy-D-ribos-5-yl)-L-
CC         homocysteine + adenine; Xref=Rhea:RHEA:17805, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:16708, ChEBI:CHEBI:57856, ChEBI:CHEBI:58195; EC=3.2.2.9;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01684};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=S-methyl-5'-thioadenosine + H2O = 5-(methylsulfanyl)-D-ribose
CC         + adenine; Xref=Rhea:RHEA:13617, ChEBI:CHEBI:15377,
CC         ChEBI:CHEBI:16708, ChEBI:CHEBI:17509, ChEBI:CHEBI:78440; EC=3.2.2.9;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01684};
CC   -!- CATALYTIC ACTIVITY:
CC       Reaction=5'-deoxyadenosine + H2O = 5-deoxy-D-ribose + adenine;
CC         Xref=Rhea:RHEA:29859, ChEBI:CHEBI:15377, ChEBI:CHEBI:16708,
CC         ChEBI:CHEBI:17319, ChEBI:CHEBI:149540; EC=3.2.2.9;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01684};
CC       PhysiologicalDirection=left-to-right; Xref=Rhea:RHEA:29860;
CC         Evidence={ECO:0000255|HAMAP-Rule:MF_01684};
CC   -!- PATHWAY: Amino-acid biosynthesis; L-methionine biosynthesis via salvage
CC       pathway; S-methyl-5-thio-alpha-D-ribose 1-phosphate from S-methyl-5'-
CC       thioadenosine (hydrolase route): step 1/2. {ECO:0000255|HAMAP-
CC       Rule:MF_01684}.
CC   -!- SUBUNIT: Homodimer. {ECO:0000255|HAMAP-Rule:MF_01684}.
CC   -!- SIMILARITY: Belongs to the PNP/UDP phosphorylase family. MtnN
CC       subfamily. {ECO:0000255|HAMAP-Rule:MF_01684}.
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; CP000783; ABU78403.1; -; Genomic_DNA.
DR   RefSeq; WP_007896708.1; NC_009778.1.
DR   AlphaFoldDB; A7MGS5; -.
DR   SMR; A7MGS5; -.
DR   GeneID; 56731871; -.
DR   KEGG; esa:ESA_03181; -.
DR   HOGENOM; CLU_031248_2_2_6; -.
DR   OMA; AAFCMNT; -.
DR   UniPathway; UPA00904; UER00871.
DR   Proteomes; UP000000260; Chromosome.
DR   GO; GO:0005829; C:cytosol; IEA:TreeGrafter.
DR   GO; GO:0008782; F:adenosylhomocysteine nucleosidase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0008930; F:methylthioadenosine nucleosidase activity; IEA:UniProtKB-UniRule.
DR   GO; GO:0033353; P:L-methionine cycle; IEA:InterPro.
DR   GO; GO:0046124; P:purine deoxyribonucleoside catabolic process; IEA:UniProtKB-UniRule.
DR   CDD; cd09008; MTAN; 1.
DR   FunFam; 3.40.50.1580:FF:000001; MTA/SAH nucleosidase family protein; 1.
DR   Gene3D; 3.40.50.1580; Nucleoside phosphorylase domain; 1.
DR   HAMAP; MF_01684; Salvage_MtnN; 1.
DR   InterPro; IPR010049; MTA_SAH_Nsdase.
DR   InterPro; IPR000845; Nucleoside_phosphorylase_d.
DR   InterPro; IPR035994; Nucleoside_phosphorylase_sf.
DR   NCBIfam; TIGR01704; MTA_SAH-Nsdase; 1.
DR   NCBIfam; NF004079; PRK05584.1; 1.
DR   PANTHER; PTHR46832; 5'-METHYLTHIOADENOSINE/S-ADENOSYLHOMOCYSTEINE NUCLEOSIDASE; 1.
DR   PANTHER; PTHR46832:SF1; 5'-METHYLTHIOADENOSINE_S-ADENOSYLHOMOCYSTEINE NUCLEOSIDASE; 1.
DR   Pfam; PF01048; PNP_UDP_1; 1.
DR   SUPFAM; SSF53167; Purine and uridine phosphorylases; 1.
PE   3: Inferred from homology;
KW   Amino-acid biosynthesis; Hydrolase; Methionine biosynthesis;
KW   Reference proteome.
FT   CHAIN           1..232
FT                   /note="5'-methylthioadenosine/S-adenosylhomocysteine
FT                   nucleosidase"
FT                   /id="PRO_0000359289"
FT   ACT_SITE        12
FT                   /note="Proton acceptor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01684"
FT   ACT_SITE        197
FT                   /note="Proton donor"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01684"
FT   BINDING         78
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01684"
FT   BINDING         152
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01684"
FT   BINDING         173..174
FT                   /ligand="substrate"
FT                   /evidence="ECO:0000255|HAMAP-Rule:MF_01684"
SQ   SEQUENCE   232 AA;  24494 MW;  E0CE34A9B429AE4B CRC64;
     MKAGIIGAME EEVTLLRDKI DNRQTLTIAG CEIYTGTLNG VDVALLKSGI GKVSAAMGAT
     LLLEHCKPDV IINTGSAGGL APSLKVGDIV VSDEVRYHDA DVTAFGYEYG QMAGCPAAFK
     ADEKLIAAAQ ETIEKLNLHA VRGLVVSGDA FINGSVNLAK IRHNFPQAIA VEMEATAIGH
     VCHNFGVPFV VVRAISDVAD QQSHLSFEEF LAVAAKQSSL MVETLLTSLN RG
//