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HAMAP rule MF_03155

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General rule information [?]

Accession MF_03155
Dates 23-NOV-2011 (Created)
1-JUN-2023 (Last updated, Version 14)
Name MTAP_euk
Scope
Eukaryota
Templates Q97W94 (MTAP_SACS2); Q8U4Q8 (MTAP_PYRFU); Q8U2I1 (PNPH_PYRFU); Q9HZK1 (MTIP_PSEAE); Q13126 (MTAP_HUMAN): [Recover all]
case <OC:Eukaryota>
Triggered by
end case


Propagated annotation [?]


Identifier, protein and gene names [?]

case <FT:3=D-x-D> and <FT:7=S> and <FT:8=[AVMI]>
Identifier
MTAP
Protein name
RecName: Full=S-methyl-5'-thioadenosine phosphorylase;
EC 2.4.2.28;
AltName: Full=5'-methylthioadenosine phosphorylase;
Short=MTA phosphorylase;
Short=MTAPase;
Short=MTAP;
case <OC:Vertebrata>
Gene name
MTAP
end case

case <OC:Saccharomycotina>
Gene name
MEU1
end case

else case <FT:3=N-x-A> and <FT:7=E> and <FT:8=[AVMI]>
Identifier
MTIP
Protein name
RecName: Full=Probable S-methyl-5'-thioinosine phosphorylase;
EC 2.4.2.44;
AltName: Full=5'-methylthioinosine phosphorylase;
Short=MTI phosphorylase;
Short=MTIP;
else case <FT:3=N-x-A> and <FT:7=E> and not <FT:8=[AVMI]>
Identifier
PNPH
Protein name
RecName: Full=Probable 6-oxopurine nucleoside phosphorylase;
EC 2.4.2.1;
AltName: Full=Purine nucleoside phosphorylase;
Short=PNP;
else
Identifier
PNPH
Protein name
RecName: Full=Purine nucleoside phosphorylase;
Short=PNP;
EC 2.4.2.1;
end case

Comments [?]

case <FT:3=D-x-D> and <FT:7=S> and <FT:8=[AVMI]>
Function Catalyzes the reversible phosphorylation of S-methyl-5'-thioadenosine (MTA) to adenine and 5-methylthioribose-1-phosphate. Involved in the breakdown of MTA, a major by-product of polyamine biosynthesis. Responsible for the first step in the methionine salvage pathway after MTA has been generated from S-adenosylmethionine. Has broad substrate specificity with 6-aminopurine nucleosides as preferred substrates.
Catalytic activity RHEA:11852: phosphate + S-methyl-5'-thioadenosine = adenine + S-methyl-5-thio-alpha-D-ribose 1-phosphate
EC 2.4.2.28
Pathway Amino-acid biosynthesis; L-methionine biosynthesis via salvage pathway; S-methyl-5-thio-alpha-D-ribose 1-phosphate from S-methyl-5'-thioadenosine (phosphorylase route): step 1/1.
else case <FT:3=N-x-A> and <FT:7=E> and <FT:8=[AVMI]>
Function Catalyzes the reversible phosphorylation of S-methyl-5'-thioinosine (MTI) to hypoxanthine and 5-methylthioribose-1-phosphate. Involved in the breakdown of S-methyl-5'-thioadenosine (MTA), a major by-product of polyamine biosynthesis. Catabolism of (MTA) occurs via deamination to MTI and phosphorolysis to hypoxanthine.
Catalytic activity RHEA:30643: phosphate + S-methyl-5'-thioinosine = hypoxanthine + S-methyl-5-thio-alpha-D-ribose 1-phosphate
EC 2.4.2.44
Pathway Purine metabolism; purine nucleoside salvage.
Miscellaneous Although this enzyme belongs to the family of MTA phosphorylases based on sequence homology, it has been shown that conserved amino acid substitutions in the substrate binding pocket convert the substrate specificity of this enzyme from 6-aminopurines to 6-oxopurines.
else case <FT:3=N-x-A> and <FT:7=E>
Function Purine nucleoside phosphorylase which is highly specific for 6-oxopurine nucleosides. Cleaves guanosine or inosine to respective bases and sugar-1-phosphate molecules. Involved in purine salvage.
Catalytic activity RHEA:19805: a purine D-ribonucleoside + phosphate = a purine nucleobase + alpha-D-ribose 1-phosphate
EC 2.4.2.1
Pathway Purine metabolism; purine nucleoside salvage.
Miscellaneous Although this enzyme belongs to the family of MTA phosphorylases based on sequence homology, it has been shown that conserved amino acid substitutions in the substrate binding pocket convert the substrate specificity of this enzyme from 6-aminopurines to 6-oxopurines.
else
Function Purine nucleoside phosphorylase involved in purine salvage.
Catalytic activity RHEA:19805: a purine D-ribonucleoside + phosphate = a purine nucleobase + alpha-D-ribose 1-phosphate
EC 2.4.2.1
Pathway Purine metabolism; purine nucleoside salvage.
Miscellaneous Although this enzyme belongs to the family of MTA phosphorylases based on sequence homology, it lacks several conserved amino acids in the substrate binding pocket that confer specificity towards MTA.
end case
Subcellular location Cytoplasm. Nucleus.
Subunit Homotrimer.
Similarity Belongs to the PNP/MTAP phosphorylase family. MTAP subfamily.

Keywords [?]

Cytoplasm
Glycosyltransferase
Nucleus
Purine salvage
Transferase

Gene Ontology [?]

GO:0005737; Cellular component: cytoplasm.
GO:0005634; Cellular component: nucleus.
case <FT:3=D-x-D> and <FT:7=S> and <FT:8=[AVI]>
GO:0017061; Molecular function: S-methyl-5-thioadenosine phosphorylase activity.
GO:0019509; Biological process: L-methionine salvage from methylthioadenosine.
else
GO:0016763; Molecular function: pentosyltransferase activity.
GO:0006166; Biological process: purine ribonucleoside salvage.
end case

Cross-references [?]

PROSITE PS01240; PNP_MTAP_2; 1;
Pfam PF01048; PNP_UDP_1; 1;
NCBIfam TIGR01694; MTAP; 1;

Features [?]

From: MTAP_SACS2 (Q97W94)
Key     From     To       Description   Tag   Condition   FTGroup
BINDING     58     59       /ligand="phosphate" /ligand_id="ChEBI:CHEBI:43474     R-[HN]  
BINDING (Optional)     91     92       /ligand="phosphate" /ligand_id="ChEBI:CHEBI:43474     [ST]-A  
BINDING     214     216       /ligand="substrate     [DN]-x-[DA]  
BINDING     16     16       /ligand="phosphate" /ligand_id="ChEBI:CHEBI:43474     [ST]  
BINDING     190     190       /ligand="substrate     M  
BINDING     191     191       /ligand="phosphate" /ligand_id="ChEBI:CHEBI:43474     [ST]  
From: PNPH_PYRFU (Q8U2I1)
SITE     169     169       Important for substrate specificity     [SE]  
SITE     223     223       Important for substrate specificity        

Additional information [?]

Size range 278-355 amino acids
Related rules None
Fusion None


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