MTNN_ECODH
ID MTNN_ECODH Reviewed; 232 AA.
AC B1XD29;
DT 20-JAN-2009, integrated into UniProtKB/Swiss-Prot.
DT 20-MAY-2008, sequence version 1.
DT 03-AUG-2022, entry version 78.
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=ECDH10B_0139;
OS Escherichia coli (strain K12 / DH10B).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Escherichia.
OX NCBI_TaxID=316385;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=K12 / DH10B;
RX PubMed=18245285; DOI=10.1128/jb.01695-07;
RA Durfee T., Nelson R., Baldwin S., Plunkett G. III, Burland V., Mau B.,
RA Petrosino J.F., Qin X., Muzny D.M., Ayele M., Gibbs R.A., Csorgo B.,
RA Posfai G., Weinstock G.M., Blattner F.R.;
RT "The complete genome sequence of Escherichia coli DH10B: insights into the
RT biology of a laboratory workhorse.";
RL J. Bacteriol. 190:2597-2606(2008).
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; CP000948; ACB01338.1; -; Genomic_DNA.
DR RefSeq; WP_000689844.1; NC_010473.1.
DR AlphaFoldDB; B1XD29; -.
DR SMR; B1XD29; -.
DR GeneID; 66671551; -.
DR KEGG; ecd:ECDH10B_0139; -.
DR HOGENOM; CLU_031248_2_2_6; -.
DR OMA; DQFVHSK; -.
DR BioCyc; ECOL316385:ECDH10B_RS00705-MON; -.
DR UniPathway; UPA00904; UER00871.
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..232
FT /note="5'-methylthioadenosine/S-adenosylhomocysteine
FT nucleosidase"
FT /id="PRO_0000359294"
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; 24354 MW; 9B1FF9BEC39D4F2C CRC64;
MKIGIIGAME EEVTLLRDKI ENRQTISLGG CEIYTGQLNG TEVALLKSGI GKVAAALGAT
LLLEHCKPDV IINTGSAGGL APTLKVGDIV VSDEARYHDA DVTAFGYEYG QLPGCPAGFK
ADDKLIAAAE ACIAELNLNA VRGLIVSGDA FINGSVGLAK IRHNFPQAIA VEMEATAIAH
VCHNFNVPFV VVRAISDVAD QQSHLSFDEF LAVAAKQSSL MVESLVQKLA HG
