MTNN_BUCAP
ID MTNN_BUCAP Reviewed; 235 AA.
AC O51931;
DT 30-MAY-2000, integrated into UniProtKB/Swiss-Prot.
DT 01-JUN-1998, sequence version 1.
DT 03-AUG-2022, entry version 114.
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}; Synonyms=mtn;
GN OrderedLocusNames=BUsg_204;
OS Buchnera aphidicola subsp. Schizaphis graminum (strain Sg).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Erwiniaceae; Buchnera.
OX NCBI_TaxID=198804;
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=9425245; DOI=10.1007/s002849900284;
RA Baumann L., Baumann P.;
RT "Characterization of ftsZ, the cell division gene of Buchnera aphidicola
RT (endosymbiont of aphids) and detection of the product.";
RL Curr. Microbiol. 36:85-89(1998).
RN [2]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=Sg;
RX PubMed=12089438; DOI=10.1126/science.1071278;
RA Tamas I., Klasson L., Canbaeck B., Naeslund A.K., Eriksson A.-S.,
RA Wernegreen J.J., Sandstroem J.P., Moran N.A., Andersson S.G.E.;
RT "50 million years of genomic stasis in endosymbiotic bacteria.";
RL Science 296:2376-2379(2002).
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=H2O + S-adenosyl-L-homocysteine = adenine + S-(5-deoxy-D-
CC ribos-5-yl)-L-homocysteine; 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=H2O + S-methyl-5'-thioadenosine = 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}.
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DR EMBL; AF012886; AAC46071.1; -; Genomic_DNA.
DR EMBL; AE013218; AAM67768.1; -; Genomic_DNA.
DR RefSeq; WP_011053735.1; NC_004061.1.
DR AlphaFoldDB; O51931; -.
DR SMR; O51931; -.
DR STRING; 198804.BUsg_204; -.
DR EnsemblBacteria; AAM67768; AAM67768; BUsg_204.
DR KEGG; bas:BUsg_204; -.
DR eggNOG; COG0775; Bacteria.
DR HOGENOM; CLU_031248_2_2_6; -.
DR OMA; DQFVHSK; -.
DR OrthoDB; 1860206at2; -.
DR UniPathway; UPA00904; UER00871.
DR Proteomes; UP000000416; Chromosome.
DR GO; GO:0005737; C:cytoplasm; IEA:UniProt.
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:0019509; P:L-methionine salvage from methylthioadenosine; IEA:UniProtKB-UniPathway.
DR GO; GO:0019284; P:L-methionine salvage from S-adenosylmethionine; IEA:UniProtKB-UniRule.
DR GO; GO:0046124; P:purine deoxyribonucleoside catabolic process; IEA:UniProtKB-UniRule.
DR Gene3D; 3.40.50.1580; -; 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 Pfam; PF01048; PNP_UDP_1; 1.
DR SUPFAM; SSF53167; SSF53167; 1.
DR TIGRFAMs; TIGR01704; MTA/SAH-Nsdase; 1.
PE 3: Inferred from homology;
KW Amino-acid biosynthesis; Hydrolase; Methionine biosynthesis.
FT CHAIN 1..235
FT /note="5'-methylthioadenosine/S-adenosylhomocysteine
FT nucleosidase"
FT /id="PRO_0000164437"
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 235 AA; 26103 MW; 9E10DBDE31BAF0E7 CRC64;
MKIGIIGAIE QEIRKIKEII NNLKIKKIGN IKIYTGTFKK IEIFLILSGI GKVSASMSTT
ISINLFQPDF IINSGSAGSL NACLKIGDII IPKKTCYYDV DLTNFGYSKG QIPEYPQTFK
TNKNLREILK EIAVEFKFKF LTGLLVTGDS FIRKSNCIKK IKNQFSSAIG VDMESTAIGQ
VCHNFKIPFI IIKSISDLSD NNATSHFEKN IPIASLKSSK LVKLLLKKIS SQNSI
