MTNN_KLEP7
ID MTNN_KLEP7 Reviewed; 232 AA.
AC A6T4W3;
DT 20-JAN-2009, integrated into UniProtKB/Swiss-Prot.
DT 21-AUG-2007, sequence version 1.
DT 03-AUG-2022, entry version 82.
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=KPN78578_01730; ORFNames=KPN_00174;
OS Klebsiella pneumoniae subsp. pneumoniae (strain ATCC 700721 / MGH 78578).
OC Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC Enterobacteriaceae; Klebsiella/Raoultella group; Klebsiella.
OX NCBI_TaxID=272620;
RN [1]
RP NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC STRAIN=ATCC 700721 / MGH 78578;
RG The Klebsiella pneumonia Genome Sequencing Project;
RA McClelland M., Sanderson E.K., Spieth J., Clifton W.S., Latreille P.,
RA Sabo A., Pepin K., Bhonagiri V., Porwollik S., Ali J., Wilson R.K.;
RL Submitted (SEP-2006) to the EMBL/GenBank/DDBJ databases.
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; CP000647; ABR75634.1; -; Genomic_DNA.
DR RefSeq; WP_002889282.1; NC_009648.1.
DR PDB; 4G89; X-ray; 2.10 A; A/B=1-232.
DR PDBsum; 4G89; -.
DR AlphaFoldDB; A6T4W3; -.
DR SMR; A6T4W3; -.
DR STRING; 272620.KPN_00174; -.
DR jPOST; A6T4W3; -.
DR EnsemblBacteria; ABR75634; ABR75634; KPN_00174.
DR KEGG; kpn:KPN_00174; -.
DR HOGENOM; CLU_031248_2_2_6; -.
DR OMA; DQFVHSK; -.
DR UniPathway; UPA00904; UER00871.
DR Proteomes; UP000000265; 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 1: Evidence at protein level;
KW 3D-structure; Amino-acid biosynthesis; Hydrolase; Methionine biosynthesis;
KW Reference proteome.
FT CHAIN 1..232
FT /note="5'-methylthioadenosine/S-adenosylhomocysteine
FT nucleosidase"
FT /id="PRO_0000359311"
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"
FT STRAND 3..9
FT /evidence="ECO:0007829|PDB:4G89"
FT HELIX 10..18
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 21..28
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 31..38
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 41..47
FT /evidence="ECO:0007829|PDB:4G89"
FT HELIX 52..66
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 69..79
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 89..99
FT /evidence="ECO:0007829|PDB:4G89"
FT HELIX 103..105
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 117..120
FT /evidence="ECO:0007829|PDB:4G89"
FT HELIX 123..136
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 140..147
FT /evidence="ECO:0007829|PDB:4G89"
FT HELIX 155..164
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 168..174
FT /evidence="ECO:0007829|PDB:4G89"
FT HELIX 175..185
FT /evidence="ECO:0007829|PDB:4G89"
FT STRAND 189..197
FT /evidence="ECO:0007829|PDB:4G89"
FT HELIX 203..230
FT /evidence="ECO:0007829|PDB:4G89"
SQ SEQUENCE 232 AA; 24504 MW; 53E8C78E7E7AD608 CRC64;
MKIGIIGAME EEVTLLRDKI ENRQTITIGG SEIYTGQLHG VDVALLKSGI GKVAAAMGAT
LLLERCQPDV IINTGSAGGL ASTLKVGDIV VSDEARYHDA DVTAFGYEYG QLPGCPAGFK
ADEKLVAAAE SCIKALDLNA VRGLIVSGDA FINGSVGLAK IRHNFPQAIA VEMEATAIAH
VCHNFKVPFV VVRAISDVAD QQSHLSFEEF LAVAARQSTL MVENLVQNLA RG
