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Reviewed, UniProtKB/Swiss-Prot P0AF12 (MTNN_ECOLI)

Last modified November 3, 2009. Version 44. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (4) | Third-party data | Customize display text xml rdf/xml gff fasta
Names and origin · Protein attributes · General annotation (Comments) · Ontologies · Sequence annotation (Features) · Sequences · References · Cross-references · Entry information · Relevant documents

Names and origin

Protein namesRecommended name:
    5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase
      Short name=MTA/SAH nucleosidase
      Short name=MTAN
    EC=3.2.2.9
Alternative name(s):
    5'-methylthioadenosine nucleosidase
      Short name=MTA nucleosidase
    S-adenosylhomocysteine nucleosidase
      Short name=SAH nucleosidase
      Short name=AdoHcy nucleosidase
      Short name=SRH nucleosidase
    P46
Gene names
Name: mtnN
Synonyms: mtn, pfs, yadA
Ordered Locus Names: b0159, JW0155
OrganismEscherichia coli (strain K12) [Complete proteome] [HAMAP]
Taxonomic identifier83333 [NCBI]
Taxonomic lineageBacteriaProteobacteriaGammaproteobacteriaEnterobacterialesEnterobacteriaceaeEscherichia

Protein attributes

Sequence length232 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is not processed.
Protein existenceEvidence at protein level.

General annotation (Comments)

Function

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. Can also use 5'-isobutylthioadenosine, 5'-n-butylthioadenosine, S-adenosyl-D-homocysteine, decarboxylated adenosylhomocysteine, deaminated adenosylhomocysteine and S-2-aza-adenosylhomocysteine as substrates. HAMAP MF_01684

Catalytic activity

S-adenosyl-L-homocysteine + H2O = S-(5-deoxy-D-ribos-5-yl)-L-homocysteine + adenine. HAMAP MF_01684

S-methyl-5'-thioadenosine + H2O = S-methyl-5-thio-D-ribose + adenine. HAMAP MF_01684

Enzyme regulation

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. Ref.7 Ref.8 Ref.10 Ref.11

Pathway

Amino-acid biosynthesis; L-methionine biosynthesis via salvage pathway; S-methyl-5-thio-alpha-D-ribose 1-phosphate from S-methyl-5'-thioadenosine (hydrolase route): step 1/2. HAMAP MF_01684

Subunit structure

Homodimer. Ref.9

Sequence similarities

Belongs to the PNP/UDP phosphorylase family. MtnN subfamily.

Biophysicochemical properties

Kinetic parameters:

KM=0.43 µM for 5'-methylthioadenosine (at pH 7 and 37 degrees Celsius) HAMAP MF_01684

KM=4.3 µM for S-adenosylhomocysteine (at pH 7 and 37 degrees Celsius)

Vmax=373 µmol/min/mg enzyme with 5'-methylthioadenosine as substrate (at pH 7 and 37 degrees Celsius)

Vmax=156 µmol/min/mg enzyme with S-adenosylhomocysteine as substrate (at pH 7 and 37 degrees Celsius)

pH dependence:

Exhibits activity across a broad pH range. Enzyme activity is moderately improved under acidic conditions.

Temperature dependence:

Optimum temperature is 37-45 degrees Celsius. Rapidly inactivated after exposure for 10 min at 55 degrees Celsius.

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 2322325'-methylthioadenosine/S-adenosylhomocysteine nucleosidase HAMAP MF_01684
PRO_0000164439

Regions

Region173 – 1742Substrate binding HAMAP MF_01684

Sites

Active site121Proton acceptor Probable
Binding site781Substrate; via amide nitrogen HAMAP MF_01684
Binding site1521Substrate; via amide nitrogen and carbonyl oxygen HAMAP MF_01684
Binding site1971Substrate HAMAP MF_01684

Experimental info

Mutagenesis121E → Q: Loss of nucleosidase activity. Ref.12
Mutagenesis1971D → N: Alters the hydrogen bond network in the active site. Ref.12
Sequence conflict212 – 23221AVAAK…KLAHG → LLPLNSPA in AAA23678. Ref.1
Sequence conflict212 – 23221AVAAK…KLAHG → LLPLNSPA in AAA24322. Ref.1

Secondary structure

.................................. 232
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
P0AF12-1 [UniParc].

Last modified December 20, 2005. Version 1.
Checksum: 9B1FF9BEC39D4F2C

FASTA23224,354
        10         20         30         40         50         60 
MKIGIIGAME EEVTLLRDKI ENRQTISLGG CEIYTGQLNG TEVALLKSGI GKVAAALGAT 

        70         80         90        100        110        120 
LLLEHCKPDV IINTGSAGGL APTLKVGDIV VSDEARYHDA DVTAFGYEYG QLPGCPAGFK 

       130        140        150        160        170        180 
ADDKLIAAAE ACIAELNLNA VRGLIVSGDA FINGSVGLAK IRHNFPQAIA VEMEATAIAH 

       190        200        210        220        230 
VCHNFNVPFV VVRAISDVAD QQSHLSFDEF LAVAAKQSSL MVESLVQKLA HG 

« Hide

References

« Hide 'large scale' references
[1]"Structure and regulation of the gene for dGTP triphosphohydrolase from Escherichia coli."
Wurgler S.M., Richardson C.C.
Proc. Natl. Acad. Sci. U.S.A. 87:2740-2744(1990) [PubMed: 2157212] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA].
Strain: K12.
[2]"Cloning and expression of Escherichia coli 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase: identification of the pfs gene product."
Cornell K.A., Riscoe M.K.
Biochim. Biophys. Acta 1396:8-14(1998) [PubMed: 9524204] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [GENOMIC DNA], CHARACTERIZATION.
[3]"Systematic sequencing of the Escherichia coli genome: analysis of the 2.4-4.1 min (110,917-193,643 bp) region."
Fujita N., Mori H., Yura T., Ishihama A.
Nucleic Acids Res. 22:1637-1639(1994) [PubMed: 8202364] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[4]"Sequence of minutes 4-25 of Escherichia coli."
Chung E., Allen E., Araujo R., Aparicio A.M., Davis K., Duncan M., Federspiel N., Hyman R., Kalman S., Komp C., Kurdi O., Lew H., Lin D., Namath A., Oefner P., Roberts D., Schramm S., Davis R.W.
Submitted (JAN-1997) to the EMBL/GenBank/DDBJ databases
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: K12 / MG1655 / ATCC 47076.
[5]"The complete genome sequence of Escherichia coli K-12."
Blattner F.R., Plunkett G. III, Bloch C.A., Perna N.T., Burland V., Riley M., Collado-Vides J., Glasner J.D., Rode C.K., Mayhew G.F., Gregor J., Davis N.W., Kirkpatrick H.A., Goeden M.A., Rose D.J., Mau B., Shao Y.
Science 277:1453-1474(1997) [PubMed: 9278503] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: K12 / MG1655 / ATCC 47076.
[6]"Highly accurate genome sequences of Escherichia coli K-12 strains MG1655 and W3110."
Hayashi K., Morooka N., Yamamoto Y., Fujita K., Isono K., Choi S., Ohtsubo E., Baba T., Wanner B.L., Mori H., Horiuchi T.
Mol. Syst. Biol. 2:E1-E5(2006) [PubMed: 16738553] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
Strain: K12 / W3110 / ATCC 27325 / DSM 5911.
[7]"Escherichia coli S-adenosylhomocysteine/5'-methylthioadenosine nucleosidase. Purification, substrate specificity and mechanism of action."
Della Ragione F., Porcelli M., Carteni-Farina M., Zappia V., Pegg A.E.
Biochem. J. 232:335-341(1985) [PubMed: 3911944] [Abstract]
Cited for: BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION.
[8]"Characterization of recombinant Eschericha coli 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase: analysis of enzymatic activity and substrate specificity."
Cornell K.A., Swarts W.E., Barry R.D., Riscoe M.K.
Biochem. Biophys. Res. Commun. 228:724-732(1996) [PubMed: 8941345] [Abstract]
Cited for: BIOPHYSICOCHEMICAL PROPERTIES, ENZYME REGULATION.
[9]"Structure of E. coli 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase reveals similarity to the purine nucleoside phosphorylases."
Lee J.E., Cornell K.A., Riscoe M.K., Howell P.L.
Structure 9:941-953(2001) [PubMed: 11591349] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (1.9 ANGSTROMS) IN COMPLEX WITH SUBSTRATE, SUBUNIT.
[10]"Structure of Escherichia coli 5'-methylthioadenosine/ S-adenosylhomocysteine nucleosidase inhibitor complexes provide insight into the conformational changes required for substrate binding and catalysis."
Lee J.E., Cornell K.A., Riscoe M.K., Howell P.L.
J. Biol. Chem. 278:8761-8770(2003) [PubMed: 12496243] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS) IN COMPLEX WITH SUBSTRATE ANALOGS, ENZYME REGULATION.
[11]"Femtomolar transition state analogue inhibitors of 5'-methylthioadenosine/S-adenosylhomocysteine nucleosidase from Escherichia coli."
Singh V., Evans G.B., Lenz D.H., Mason J.M., Clinch K., Mee S., Painter G.F., Tyler P.C., Furneaux R.H., Lee J.E., Howell P.L., Schramm V.L.
J. Biol. Chem. 280:18265-18273(2005) [PubMed: 15749708] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS) IN COMPLEX WITH SUBSTRATE ANALOGS, ENZYME REGULATION.
[12]"Structural snapshots of MTA/AdoHcy nucleosidase along the reaction coordinate provide insights into enzyme and nucleoside flexibility during catalysis."
Lee J.E., Smith G.D., Horvatin C., Huang D.J., Cornell K.A., Riscoe M.K., Howell P.L.
J. Mol. Biol. 352:559-574(2005) [PubMed: 16109423] [Abstract]
Cited for: X-RAY CRYSTALLOGRAPHY (2.1 ANGSTROMS) IN COMPLEX WITH SUBSTRATE ANALOGS, MUTANTS GLN-197 AND GLN-12, REACTION MECHANISM, MUTAGENESIS OF GLU-12 AND ASP-197.
+Additional computationally mapped references.

Cross-references

Sequence databases

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.
PIRS45227.
RefSeqAP_000820.1.
NP_414701.1.

3D structure databases

EntryMethodResolution (Å)ChainPositionsPDBsum
1JYSX-ray1.90A/B1-232[»]
1NC1X-ray2.00A/B1-232[»]
1NC3X-ray2.20A/B1-232[»]
1Y6QX-ray2.20A/B1-232[»]
1Y6RX-ray2.20A/B1-232[»]
1Z5NX-ray2.10A/B1-232[»]
1Z5OX-ray2.00A/B1-232[»]
1Z5PX-ray2.00A1-232[»]
ModBaseSearch...

Protein-protein interaction databases

STRINGP0AF12.

2-D gel databases

SWISS-2DPAGEP0AF12.
ECO2DBASEC025.4. 6TH EDITION.

Genome annotation databases

GeneID948542.
GenomeReviewsGene locus JW0155 in contig AP009048_GR.
Gene locus b0159 in contig U00096_GR.
KEGGecj:JW0155.
eco:b0159.

Organism-specific databases

EchoBASEEB1082.
EcoGeneEG11090. pfs.
CMRSearch...

Phylogenomic databases

HOGENOMP0AF12.
OMAAQVCHQF.

Enzyme and pathway databases

BioCycEcoCyc:EG11090-MON.
MetaCyc:EG11090-MON.

Gene expression databases

GenevestigatorP0AF12.

Family and domain databases

HAMAPMF_01684.
[Tree]
InterProIPR010049. MTA_SAH_Nsdase.
IPR000845. Nucleoside_phosphorylase.
IPR018017. Nucleoside_phosphorylase_1.
[Graphical view]
PANTHERPTHR21234. PNP_UDP. 1 hit.
PfamPF01048. PNP_UDP_1. 1 hit.
[Graphical view]
TIGRFAMsTIGR01704. MTA/SAH-Nsdase. 1 hit.
ProtoNetSearch...

Other Resources

DrugBankDB00173. Adenine.

Entry information

Entry nameMTNN_ECOLI
AccessionPrimary (citable) accession number: P0AF12
Secondary accession number(s): P24247
Entry history
Integrated into UniProtKB/Swiss-Prot: December 20, 2005
Last sequence update: December 20, 2005
Last modified: November 3, 2009
This is version 44 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation projectHAMAP (High-quality Automated and Manual Annotation of microbial Proteomes)

Relevant documents

Escherichia coli

Escherichia coli (strain K12): entries and cross-references to EcoGene

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

Names and origin · Protein attributes · General annotation (Comments) · Ontologies · Sequence annotation (Features) · Sequences · References · Cross-references · Entry information · Relevant documents