UniProtKB - P0AF12 (MTNN_ECOLI)
Protein
5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase
Gene
mtnN
Organism
Escherichia coli (strain K12)
Status
Functioni
Catalyzes the irreversible cleavage of the glycosidic bond in both 5'-methylthioadenosine (MTA) and S-adenosylhomocysteine (SAH/AdoHcy) to adenine and the corresponding thioribose, 5'-methylthioribose and S-ribosylhomocysteine, respectively (PubMed:3911944, PubMed:16101288). Also cleaves 5'-deoxyadenosine, a toxic by-product of radical S-adenosylmethionine (SAM) enzymes, into 5-deoxyribose and adenine. Thus, is required for in vivo function of the radical SAM enzymes biotin synthase and lipoic acid synthase, that are inhibited by 5'-deoxyadenosine accumulation (PubMed:15911379). Can also use 5'-isobutylthioadenosine, 5'-n-butylthioadenosine, S-adenosyl-D-homocysteine, decarboxylated adenosylhomocysteine, deaminated adenosylhomocysteine and S-2-aza-adenosylhomocysteine as substrates in vitro (PubMed:3911944).3 Publications
Catalytic activityi
- H2O + S-adenosyl-L-homocysteine = adenine + S-(5-deoxy-D-ribos-5-yl)-L-homocysteineUniRule annotation2 PublicationsEC:3.2.2.9UniRule annotation2 Publications
- H2O + S-methyl-5'-thioadenosine = 5-(methylsulfanyl)-D-ribose + adenineUniRule annotation2 PublicationsEC:3.2.2.9UniRule annotation2 Publications
- EC:3.2.2.9UniRule annotation1 Publication
Activity regulationi
Strongly inhibited by aryl-substituted MTA analogs, alkyl-substituted MTA analogs, 5'-methylthioformycin, 5'-chloroformycin, S-formycinylhomocysteine, 5'-methylthiotubercidin, S-tubercidinylhomocysteine and S-8-aza-adenosylhomocysteine. Poorly inhibited by 5'-isobutylthioinosine, 5'-n-butylthioinosine, 5'-methylthio-3-deaza-adenosine, 5'-isobutylthio-3-deaza-adenosine, S-n-6-methyl-3-deaza-adenosylhomocysteine, S-adenosylhomocysteine sulphoxide and Sinefungin.4 Publications
Kineticsi
kcat is 3.0 sec(-1) and 2.6 sec(-1) with 5'-methylthioadenosine and S-adenosylhomocysteine as substrate, respectively.1 Publication
- KM=0.4 µM for 5'-methylthioadenosine (at pH 7 and 37 degrees Celsius)1 Publication
- KM=0.8 µM for 5'-methylthioadenosine (at pH 7 and 22 degrees Celsius)1 Publication
- KM=4.3 µM for S-adenosylhomocysteine (at pH 7 and 37 degrees Celsius)1 Publication
- KM=1.3 µM for S-adenosylhomocysteine (at pH 7 and 22 degrees Celsius)1 Publication
pH dependencei
Exhibits activity across a broad pH range. Enzyme activity is moderately improved under acidic conditions.1 Publication
Temperature dependencei
Optimum temperature is 37-45 degrees Celsius. Rapidly inactivated after exposure for 10 minutes at 55 degrees Celsius.1 Publication
: L-methionine biosynthesis via salvage pathway Pathwayi
This protein is involved in step 1 of the subpathway that synthesizes S-methyl-5-thio-alpha-D-ribose 1-phosphate from S-methyl-5'-thioadenosine (hydrolase route).UniRule annotationProteins known to be involved in the 2 steps of the subpathway in this organism are:
- 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase (mtnN), 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase (mtnN)
- no protein annotated in this organism
View all proteins of this organism that are known to be involved in the subpathway that synthesizes S-methyl-5-thio-alpha-D-ribose 1-phosphate from S-methyl-5'-thioadenosine (hydrolase route), the pathway L-methionine biosynthesis via salvage pathway and in Amino-acid biosynthesis.
Sites
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Active sitei | 12 | Proton acceptorUniRule annotation1 Publication | 1 | |
Binding sitei | 78 | Substrate; via amide nitrogenUniRule annotation1 Publication | 1 | |
Binding sitei | 152 | Substrate; via amide nitrogen and carbonyl oxygenUniRule annotation1 Publication | 1 | |
Active sitei | 197 | Proton donorUniRule annotation1 Publication | 1 |
GO - Molecular functioni
- adenosylhomocysteine nucleosidase activity Source: EcoCyc
- identical protein binding Source: IntAct
- methylthioadenosine nucleosidase activity Source: EcoCyc
GO - Biological processi
- L-methionine salvage from methylthioadenosine Source: UniProtKB-UniPathway
- L-methionine salvage from S-adenosylmethionine Source: EcoCyc
- purine deoxyribonucleoside catabolic process Source: UniProtKB-UniRule
- toxic metabolite repair Source: UniProtKB
Keywordsi
Molecular function | Hydrolase |
Biological process | Amino-acid biosynthesis, Methionine biosynthesis |
Enzyme and pathway databases
BioCyci | EcoCyc:EG11090-MONOMER MetaCyc:EG11090-MONOMER |
BRENDAi | 3.2.2.30, 2026 3.2.2.9, 2026 |
UniPathwayi | UPA00904;UER00871 |
Names & Taxonomyi
Protein namesi | Recommended name: 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase1 PublicationUniRule annotation (EC:3.2.2.9UniRule annotation3 Publications)Short name: MTA/SAH nucleosidaseUniRule annotation Short name: MTAN1 PublicationUniRule annotation Alternative name(s): 5'-deoxyadenosine nucleosidaseUniRule annotation1 Publication Short name: DOA nucleosidaseUniRule annotation1 Publication Short name: dAdo nucleosidaseUniRule annotation1 Publication 5'-methylthioadenosine nucleosidaseUniRule annotation Short name: MTA nucleosidaseUniRule annotation S-adenosylhomocysteine nucleosidaseUniRule annotation Short name: AdoHcy nucleosidaseUniRule annotation Short name: SAH nucleosidaseUniRule annotation Short name: SRH nucleosidaseUniRule annotation |
Gene namesi | Name:mtnNUniRule annotation Synonyms:mtn, pfs, yadA Ordered Locus Names:b0159, JW0155 |
Organismi | Escherichia coli (strain K12) |
Taxonomic identifieri | 83333 [NCBI] |
Taxonomic lineagei | Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacterales › Enterobacteriaceae › Escherichia › |
Proteomesi |
|
Pathology & Biotechi
Disruption phenotypei
Cells lacking this gene are deficient in biotin synthase (BioB) activity in vivo due to accumulation of 5'-deoxyadenosine.1 Publication
Mutagenesis
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Mutagenesisi | 9 | M → A: 13-19% of wild-type catalytic efficiency. 1 Publication | 1 | |
Mutagenesisi | 12 | E → A or Q: Loss of catalytic activity. 1 Publication | 1 | |
Mutagenesisi | 50 | I → A: 12-23% of wild-type catalytic efficiency. 1 Publication | 1 | |
Mutagenesisi | 76 | S → A: 13-23% of wild-type catalytic efficiency. 1 Publication | 1 | |
Mutagenesisi | 151 | F → A: 0.5% of wild-type catalytic efficiency. 1 Publication | 1 | |
Mutagenesisi | 173 | M → A: 0.5% of wild-type catalytic efficiency. 1 Publication | 1 | |
Mutagenesisi | 174 | E → A or Q: Loss of catalytic activity. 1 Publication | 1 | |
Mutagenesisi | 193 | R → A: 13-28% of wild-type catalytic efficiency. 1 Publication | 1 | |
Mutagenesisi | 196 | S → A: 2-4% of wild-type catalytic efficiency. 1 Publication | 1 | |
Mutagenesisi | 197 | D → A or N: Loss of catalytic activity. 1 Publication | 1 | |
Mutagenesisi | 207 | F → A: 2% of wild-type catalytic efficiency. 1 Publication | 1 |
Chemistry databases
ChEMBLi | CHEMBL2866 |
DrugBanki | DB02158, (2S,3S,4R,5S)-2-(4-Amino-4,5-dihydro-1H-pyrrolo[3,2-d]pyrimidin-7-yl)-5-[(methylsulfanyl)methyl]-3,4-pyrrolidinediol DB08606, (3R,4S)-1-[(4-AMINO-5H-PYRROLO[3,2-D]PYRIMIDIN-7-YL)METHYL]-4-[(METHYLSULFANYL)METHYL]PYRROLIDIN-3-OL DB02933, 5'-Deoxy-5'-(Methylthio)-Tubercidin DB00173, Adenine DB02281, Formycin |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
ChainiPRO_0000164439 | 1 – 232 | 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidaseAdd BLAST | 232 |
Proteomic databases
jPOSTi | P0AF12 |
PaxDbi | P0AF12 |
PRIDEi | P0AF12 |
2D gel databases
SWISS-2DPAGEi | P0AF12 |
Interactioni
Subunit structurei
Homodimer.
UniRule annotation4 PublicationsBinary interactionsi
P0AF12
With | #Exp. | IntAct |
---|---|---|
itself | 2 | EBI-1114261,EBI-1114261 |
GO - Molecular functioni
- identical protein binding Source: IntAct
Protein-protein interaction databases
BioGRIDi | 4260991, 38 interactors 852836, 1 interactor |
DIPi | DIP-10270N |
IntActi | P0AF12, 7 interactors |
STRINGi | 511145.b0159 |
Chemistry databases
BindingDBi | P0AF12 |
Structurei
Secondary structure
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details3D structure databases
SMRi | P0AF12 |
ModBasei | Search... |
PDBe-KBi | Search... |
Miscellaneous databases
EvolutionaryTracei | P0AF12 |
Family & Domainsi
Region
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Regioni | 173 – 174 | Substrate bindingUniRule annotation | 2 |
Sequence similaritiesi
Phylogenomic databases
eggNOGi | COG0775, Bacteria |
HOGENOMi | CLU_031248_2_2_6 |
InParanoidi | P0AF12 |
PhylomeDBi | P0AF12 |
Family and domain databases
Gene3Di | 3.40.50.1580, 1 hit |
HAMAPi | MF_01684, Salvage_MtnN, 1 hit |
InterProi | View protein in InterPro IPR010049, MTA_SAH_Nsdase IPR000845, Nucleoside_phosphorylase_d IPR035994, Nucleoside_phosphorylase_sf |
Pfami | View protein in Pfam PF01048, PNP_UDP_1, 1 hit |
SUPFAMi | SSF53167, SSF53167, 1 hit |
TIGRFAMsi | TIGR01704, MTA/SAH-Nsdase, 1 hit |
i Sequence
Sequence statusi: Complete.
P0AF12-1 [UniParc]FASTAAdd to basket
10 20 30 40 50
MKIGIIGAME EEVTLLRDKI ENRQTISLGG CEIYTGQLNG TEVALLKSGI
60 70 80 90 100
GKVAAALGAT LLLEHCKPDV IINTGSAGGL APTLKVGDIV VSDEARYHDA
110 120 130 140 150
DVTAFGYEYG QLPGCPAGFK ADDKLIAAAE ACIAELNLNA VRGLIVSGDA
160 170 180 190 200
FINGSVGLAK IRHNFPQAIA VEMEATAIAH VCHNFNVPFV VVRAISDVAD
210 220 230
QQSHLSFDEF LAVAAKQSSL MVESLVQKLA HG
Sequence cautioni
The sequence AAA23678 differs from that shown. Reason: Erroneous initiation.Curated
Experimental Info
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Sequence conflicti | 212 – 232 | AVAAK…KLAHG → LLPLNSPA in AAA23678 (PubMed:2157212).CuratedAdd BLAST | 21 | |
Sequence conflicti | 212 – 232 | AVAAK…KLAHG → LLPLNSPA in AAA24322 (PubMed:2157212).CuratedAdd BLAST | 21 |
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | M31772 Genomic DNA Translation: AAA23678.1 Different initiation. U24438 Genomic DNA Translation: AAC38291.1 M83735 Genomic DNA Translation: AAA24322.1 U70214 Genomic DNA Translation: AAB08589.1 U00096 Genomic DNA Translation: AAC73270.1 AP009048 Genomic DNA Translation: BAB96736.1 |
PIRi | S45227 |
RefSeqi | NP_414701.1, NC_000913.3 WP_000689844.1, NZ_SSZK01000004.1 |
Genome annotation databases
EnsemblBacteriai | AAC73270; AAC73270; b0159 BAB96736; BAB96736; BAB96736 |
GeneIDi | 49586023 948542 |
KEGGi | ecj:JW0155 eco:b0159 |
PATRICi | fig|1411691.4.peg.2121 |
Similar proteinsi
Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | M31772 Genomic DNA Translation: AAA23678.1 Different initiation. U24438 Genomic DNA Translation: AAC38291.1 M83735 Genomic DNA Translation: AAA24322.1 U70214 Genomic DNA Translation: AAB08589.1 U00096 Genomic DNA Translation: AAC73270.1 AP009048 Genomic DNA Translation: BAB96736.1 |
PIRi | S45227 |
RefSeqi | NP_414701.1, NC_000913.3 WP_000689844.1, NZ_SSZK01000004.1 |
3D structure databases
Select the link destinations: PDBei RCSB PDBi PDBji Links Updated | PDB entry | Method | Resolution (Å) | Chain | Positions | PDBsum |
1JYS | X-ray | 1.90 | A/B | 1-232 | [»] | |
1NC1 | X-ray | 2.00 | A/B | 1-232 | [»] | |
1NC3 | X-ray | 2.20 | A/B | 1-232 | [»] | |
1Y6Q | X-ray | 2.20 | A/B | 1-232 | [»] | |
1Y6R | X-ray | 2.20 | A/B | 1-232 | [»] | |
1Z5N | X-ray | 2.10 | A/B | 1-232 | [»] | |
1Z5O | X-ray | 2.00 | A/B | 1-232 | [»] | |
1Z5P | X-ray | 2.00 | A | 1-232 | [»] | |
3O4V | X-ray | 1.75 | A/B | 1-232 | [»] | |
4WKC | X-ray | 1.64 | A | 1-232 | [»] | |
4YML | X-ray | 1.75 | A | 1-232 | [»] | |
SMRi | P0AF12 | |||||
ModBasei | Search... | |||||
PDBe-KBi | Search... |
Protein-protein interaction databases
BioGRIDi | 4260991, 38 interactors 852836, 1 interactor |
DIPi | DIP-10270N |
IntActi | P0AF12, 7 interactors |
STRINGi | 511145.b0159 |
Chemistry databases
BindingDBi | P0AF12 |
ChEMBLi | CHEMBL2866 |
DrugBanki | DB02158, (2S,3S,4R,5S)-2-(4-Amino-4,5-dihydro-1H-pyrrolo[3,2-d]pyrimidin-7-yl)-5-[(methylsulfanyl)methyl]-3,4-pyrrolidinediol DB08606, (3R,4S)-1-[(4-AMINO-5H-PYRROLO[3,2-D]PYRIMIDIN-7-YL)METHYL]-4-[(METHYLSULFANYL)METHYL]PYRROLIDIN-3-OL DB02933, 5'-Deoxy-5'-(Methylthio)-Tubercidin DB00173, Adenine DB02281, Formycin |
2D gel databases
SWISS-2DPAGEi | P0AF12 |
Proteomic databases
jPOSTi | P0AF12 |
PaxDbi | P0AF12 |
PRIDEi | P0AF12 |
Genome annotation databases
EnsemblBacteriai | AAC73270; AAC73270; b0159 BAB96736; BAB96736; BAB96736 |
GeneIDi | 49586023 948542 |
KEGGi | ecj:JW0155 eco:b0159 |
PATRICi | fig|1411691.4.peg.2121 |
Organism-specific databases
EchoBASEi | EB1082 |
Phylogenomic databases
eggNOGi | COG0775, Bacteria |
HOGENOMi | CLU_031248_2_2_6 |
InParanoidi | P0AF12 |
PhylomeDBi | P0AF12 |
Enzyme and pathway databases
UniPathwayi | UPA00904;UER00871 |
BioCyci | EcoCyc:EG11090-MONOMER MetaCyc:EG11090-MONOMER |
BRENDAi | 3.2.2.30, 2026 3.2.2.9, 2026 |
Miscellaneous databases
EvolutionaryTracei | P0AF12 |
PROi | PR:P0AF12 |
Family and domain databases
Gene3Di | 3.40.50.1580, 1 hit |
HAMAPi | MF_01684, Salvage_MtnN, 1 hit |
InterProi | View protein in InterPro IPR010049, MTA_SAH_Nsdase IPR000845, Nucleoside_phosphorylase_d IPR035994, Nucleoside_phosphorylase_sf |
Pfami | View protein in Pfam PF01048, PNP_UDP_1, 1 hit |
SUPFAMi | SSF53167, SSF53167, 1 hit |
TIGRFAMsi | TIGR01704, MTA/SAH-Nsdase, 1 hit |
ProtoNeti | Search... |
MobiDBi | Search... |
Entry informationi
Entry namei | MTNN_ECOLI | |
Accessioni | P0AF12Primary (citable) accession number: P0AF12 Secondary accession number(s): P24247 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | December 20, 2005 |
Last sequence update: | December 20, 2005 | |
Last modified: | December 2, 2020 | |
This is version 128 of the entry and version 1 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Prokaryotic Protein Annotation Program |
Miscellaneousi
Keywords - Technical termi
3D-structure, Reference proteomeDocuments
- PATHWAY comments
Index of metabolic and biosynthesis pathways - PDB cross-references
Index of Protein Data Bank (PDB) cross-references - SIMILARITY comments
Index of protein domains and families