UniProtKB - P0A9M5 (XGPT_ECOLI)
Protein
Xanthine-guanine phosphoribosyltransferase
Gene
gpt
Organism
Escherichia coli (strain K12)
Status
Functioni
Purine salvage pathway enzyme that catalyzes the transfer of the ribosyl-5-phosphate group from 5-phospho-alpha-D-ribose 1-diphosphate (PRPP) to the N9 position of the 6-oxopurines guanine and xanthine to form the corresponding ribonucleotides GMP (guanosine 5'-monophosphate) and XMP (xanthosine 5'-monophosphate), with the release of PPi. To a lesser extent, also acts on hypoxanthine (PubMed:9100006, PubMed:3886014). Does not ribophosphorylate adenine (PubMed:3886014).2 Publications
Miscellaneous
E.coli cells express two distinct 6-oxopurine PRTases, with very different specificities for hypoxanthine, guanine, and xanthine. Salvage enzymes allow a more energy efficient synthesis of purine nucleoside monophosphates compared with the de novo pathway. The kinetic analysis suggests that E.coli HPRT is mainly responsible for the synthesis of IMP and that XGPRT primarily salvages guanine and xanthine.1 Publication
Catalytic activityi
- This reaction proceeds in the backward1 Publication direction.
- EC:2.4.2.222 PublicationsThis reaction proceeds in the backward1 Publication direction.
- This reaction proceeds in the backward1 Publication direction.
Cofactori
Mg2+1 Publication
Activity regulationi
Inhibited by thioguanine, GMP and, to a lesser extent, by thioxanthine, azaxanthine and azaguanine (PubMed:3886014). Highly inhibited by nucleoside phosphonates, which are product analogs (PubMed:23927482).2 Publications
Kineticsi
kcat is 112.0 sec(-1) with guanine as substrate. kcat is 150.1 sec(-1) with xanthine as substrate. kcat is 54.8 sec(-1) with hypoxanthine as substrate (at pH 8.5).1 Publication
- KM=4.3 µM for guanine (at pH 8.5)1 Publication
- KM=30.5 µM for xanthine (at pH 8.5)1 Publication
- KM=90.8 µM for hypoxanthine (at pH 8.5)1 Publication
- KM=139 µM for 5-phospho-alpha-D-ribose 1-diphosphate (at pH 8.5)1 Publication
- KM=2.5 µM for guanine1 Publication
- KM=42 µM for xanthine1 Publication
- KM=182 µM for hypoxanthine1 Publication
- KM=38.5 µM for 5-phospho-alpha-D-ribose 1-diphosphate (with guanine as cosubstrate)1 Publication
- KM=100 µM for 5-phospho-alpha-D-ribose 1-diphosphate (with xanthine as cosubstrate)1 Publication
: GMP biosynthesis via salvage pathway Pathwayi
This protein is involved in step 1 of the subpathway that synthesizes GMP from guanine.1 PublicationProteins known to be involved in this subpathway in this organism are:
- Xanthine-guanine phosphoribosyltransferase (gpt), Xanthine-guanine phosphoribosyltransferase (gpt)
View all proteins of this organism that are known to be involved in the subpathway that synthesizes GMP from guanine, the pathway GMP biosynthesis via salvage pathway and in Purine metabolism.
Pathwayi: XMP biosynthesis via salvage pathway
This protein is involved in step 1 of the subpathway that synthesizes XMP from xanthine.1 PublicationProteins known to be involved in this subpathway in this organism are:
- Xanthine-guanine phosphoribosyltransferase (gpt), Xanthine-guanine phosphoribosyltransferase (gpt)
View all proteins of this organism that are known to be involved in the subpathway that synthesizes XMP from xanthine, the pathway XMP biosynthesis via salvage pathway and in Purine metabolism.
Sites
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Binding sitei | 69 | 5-phospho-alpha-D-ribose 1-diphosphateCombined sources1 Publication | 1 | |
Binding sitei | 69 | GMPCombined sources1 Publication | 1 | |
Metal bindingi | 89 | Magnesium1 Publication | 1 | |
Binding sitei | 92 | Xanthine or guanineCombined sources1 Publication | 1 | |
Binding sitei | 135 | Xanthine or guanine; via amide nitrogen and carbonyl oxygenCombined sources1 Publication | 1 |
Regions
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Nucleotide bindingi | 92 – 96 | GMPCombined sources1 Publication | 5 | |
Nucleotide bindingi | 134 – 135 | GMPCombined sources1 Publication | 2 |
GO - Molecular functioni
- guanosine tetraphosphate binding Source: EcoCyc
- hypoxanthine phosphoribosyltransferase activity Source: EcoCyc
- magnesium ion binding Source: EcoCyc
- xanthine phosphoribosyltransferase activity Source: EcoCyc
GO - Biological processi
- GMP salvage Source: EcoCyc
- IMP salvage Source: EcoCyc
- protein homotetramerization Source: EcoCyc
- XMP salvage Source: EcoCyc
Keywordsi
Molecular function | Glycosyltransferase, Transferase |
Biological process | Purine salvage |
Ligand | Magnesium, Metal-binding |
Enzyme and pathway databases
BioCyci | EcoCyc:GPT-MONOMER MetaCyc:GPT-MONOMER |
BRENDAi | 2.4.2.22, 2026 |
UniPathwayi | UPA00602;UER00658 UPA00909;UER00887 |
Names & Taxonomyi
Protein namesi | |
Gene namesi | Name:gpt Synonyms:gpp, gxu Ordered Locus Names:b0238, JW0228 |
Organismi | Escherichia coli (strain K12) |
Taxonomic identifieri | 83333 [NCBI] |
Taxonomic lineagei | Bacteria › Proteobacteria › Gammaproteobacteria › Enterobacterales › Enterobacteriaceae › Escherichia › |
Proteomesi |
|
Subcellular locationi
- Cell inner membrane Curated; Peripheral membrane protein Curated
GO - Cellular componenti
- cytosol Source: EcoCyc
- plasma membrane Source: UniProtKB-SubCell
Keywords - Cellular componenti
Cell inner membrane, Cell membrane, MembranePathology & Biotechi
Mutagenesis
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Mutagenesisi | 59 | C → A: No effect on catalytic activity; increased stability. 1 Publication | 1 | |
Mutagenesisi | 65 – 70 | HDNQRE → AAAAAA: No effect on affinity for xanthine and guanine substrates. However, the catalytic activity is highly reduced (200-fold when guanine is used as substrate) and the inhibition by GMP is also affected. 1 Publication | 6 |
Chemistry databases
ChEMBLi | CHEMBL3988588 |
DrugBanki | DB03942, Carboxylic PRPP DB02377, Guanine DB01972, Guanosine-5'-Monophosphate DB02134, Xanthine |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
ChainiPRO_0000139666 | 1 – 152 | Xanthine-guanine phosphoribosyltransferaseAdd BLAST | 152 |
Proteomic databases
jPOSTi | P0A9M5 |
PaxDbi | P0A9M5 |
PRIDEi | P0A9M5 |
2D gel databases
SWISS-2DPAGEi | P0A9M5 |
Interactioni
Subunit structurei
Homotetramer.
2 PublicationsProtein-protein interaction databases
BioGRIDi | 4260989, 10 interactors |
IntActi | P0A9M5, 1 interactor |
STRINGi | 511145.b0238 |
Chemistry databases
BindingDBi | P0A9M5 |
Structurei
Secondary structure
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details3D structure databases
SMRi | P0A9M5 |
ModBasei | Search... |
PDBe-KBi | Search... |
Miscellaneous databases
EvolutionaryTracei | P0A9M5 |
Family & Domainsi
Region
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Regioni | 37 – 38 | 5-phospho-alpha-D-ribose 1-diphosphate bindingCombined sources1 Publication | 2 | |
Regioni | 88 – 96 | 5-phospho-alpha-D-ribose 1-diphosphate bindingCombined sources1 Publication | 9 |
Sequence similaritiesi
Phylogenomic databases
eggNOGi | COG2236, Bacteria |
HOGENOMi | CLU_080904_3_0_6 |
InParanoidi | P0A9M5 |
PhylomeDBi | P0A9M5 |
Family and domain databases
CDDi | cd06223, PRTases_typeI, 1 hit |
Gene3Di | 3.40.50.2020, 1 hit |
HAMAPi | MF_01903, XGPRT, 1 hit |
InterProi | View protein in InterPro IPR000836, PRibTrfase_dom IPR029057, PRTase-like IPR023747, Xanthine_Guanine_PRibTrfase |
PANTHERi | PTHR39563, PTHR39563, 1 hit |
Pfami | View protein in Pfam PF00156, Pribosyltran, 1 hit |
SUPFAMi | SSF53271, SSF53271, 1 hit |
PROSITEi | View protein in PROSITE PS00103, PUR_PYR_PR_TRANSFER, 1 hit |
i Sequence
Sequence statusi: Complete.
P0A9M5-1 [UniParc]FASTAAdd to basket
10 20 30 40 50
MSEKYIVTWD MLQIHARKLA SRLMPSEQWK GIIAVSRGGL VPGALLAREL
60 70 80 90 100
GIRHVDTVCI SSYDHDNQRE LKVLKRAEGD GEGFIVIDDL VDTGGTAVAI
110 120 130 140 150
REMYPKAHFV TIFAKPAGRP LVDDYVVDIP QDTWIEQPWD MGVVFVPPIS
GR
Experimental Info
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Sequence conflicti | 122 | V → G in AAA23933 (PubMed:3540961).Curated | 1 |
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | X00221 Genomic DNA Translation: CAA25040.1 X00222 Genomic DNA Translation: CAA25041.1 M13422 Genomic DNA Translation: AAA23928.1 M12907 Genomic DNA Translation: AAA23932.1 M15035 Genomic DNA Translation: AAA23933.1 U70214 Genomic DNA Translation: AAB08658.1 U00096 Genomic DNA Translation: AAC73342.1 AP009048 Genomic DNA Translation: BAA77907.1 M10382 Genomic DNA Translation: AAA23931.1 |
PIRi | A00587, RTECGX |
RefSeqi | NP_414773.1, NC_000913.3 WP_001291990.1, NZ_SSZK01000050.1 |
Genome annotation databases
EnsemblBacteriai | AAC73342; AAC73342; b0238 BAA77907; BAA77907; BAA77907 |
GeneIDi | 58461060 944817 |
KEGGi | ecj:JW0228 eco:b0238 |
PATRICi | fig|1411691.4.peg.2045 |
Similar proteinsi
Cross-referencesi
Sequence databases
Select the link destinations: EMBLi GenBanki DDBJi Links Updated | X00221 Genomic DNA Translation: CAA25040.1 X00222 Genomic DNA Translation: CAA25041.1 M13422 Genomic DNA Translation: AAA23928.1 M12907 Genomic DNA Translation: AAA23932.1 M15035 Genomic DNA Translation: AAA23933.1 U70214 Genomic DNA Translation: AAB08658.1 U00096 Genomic DNA Translation: AAC73342.1 AP009048 Genomic DNA Translation: BAA77907.1 M10382 Genomic DNA Translation: AAA23931.1 |
PIRi | A00587, RTECGX |
RefSeqi | NP_414773.1, NC_000913.3 WP_001291990.1, NZ_SSZK01000050.1 |
3D structure databases
Select the link destinations: PDBei RCSB PDBi PDBji Links Updated | PDB entry | Method | Resolution (Å) | Chain | Positions | PDBsum |
1A95 | X-ray | 2.00 | A/B/C/D | 1-152 | [»] | |
1A96 | X-ray | 2.00 | A/B/C/D | 1-152 | [»] | |
1A97 | X-ray | 2.60 | A/B/C/D | 3-150 | [»] | |
1A98 | X-ray | 2.25 | A/B | 1-152 | [»] | |
1NUL | X-ray | 1.80 | A/B | 1-152 | [»] | |
4JIT | X-ray | 2.80 | A/B/C/D | 1-152 | [»] | |
4JLS | X-ray | 2.20 | A/B/C/D/E/H/I/J | 1-152 | [»] | |
SMRi | P0A9M5 | |||||
ModBasei | Search... | |||||
PDBe-KBi | Search... |
Protein-protein interaction databases
BioGRIDi | 4260989, 10 interactors |
IntActi | P0A9M5, 1 interactor |
STRINGi | 511145.b0238 |
Chemistry databases
BindingDBi | P0A9M5 |
ChEMBLi | CHEMBL3988588 |
DrugBanki | DB03942, Carboxylic PRPP DB02377, Guanine DB01972, Guanosine-5'-Monophosphate DB02134, Xanthine |
2D gel databases
SWISS-2DPAGEi | P0A9M5 |
Proteomic databases
jPOSTi | P0A9M5 |
PaxDbi | P0A9M5 |
PRIDEi | P0A9M5 |
Genome annotation databases
EnsemblBacteriai | AAC73342; AAC73342; b0238 BAA77907; BAA77907; BAA77907 |
GeneIDi | 58461060 944817 |
KEGGi | ecj:JW0228 eco:b0238 |
PATRICi | fig|1411691.4.peg.2045 |
Organism-specific databases
EchoBASEi | EB0409 |
Phylogenomic databases
eggNOGi | COG2236, Bacteria |
HOGENOMi | CLU_080904_3_0_6 |
InParanoidi | P0A9M5 |
PhylomeDBi | P0A9M5 |
Enzyme and pathway databases
UniPathwayi | UPA00602;UER00658 UPA00909;UER00887 |
BioCyci | EcoCyc:GPT-MONOMER MetaCyc:GPT-MONOMER |
BRENDAi | 2.4.2.22, 2026 |
Miscellaneous databases
EvolutionaryTracei | P0A9M5 |
PROi | PR:P0A9M5 |
Family and domain databases
CDDi | cd06223, PRTases_typeI, 1 hit |
Gene3Di | 3.40.50.2020, 1 hit |
HAMAPi | MF_01903, XGPRT, 1 hit |
InterProi | View protein in InterPro IPR000836, PRibTrfase_dom IPR029057, PRTase-like IPR023747, Xanthine_Guanine_PRibTrfase |
PANTHERi | PTHR39563, PTHR39563, 1 hit |
Pfami | View protein in Pfam PF00156, Pribosyltran, 1 hit |
SUPFAMi | SSF53271, SSF53271, 1 hit |
PROSITEi | View protein in PROSITE PS00103, PUR_PYR_PR_TRANSFER, 1 hit |
ProtoNeti | Search... |
MobiDBi | Search... |
Entry informationi
Entry namei | XGPT_ECOLI | |
Accessioni | P0A9M5Primary (citable) accession number: P0A9M5 Secondary accession number(s): P00501 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | July 21, 1986 |
Last sequence update: | July 21, 1986 | |
Last modified: | February 10, 2021 | |
This is version 129 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, Direct protein sequencing, 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