PRS3

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0000287 magnesium ion binding	IEA GO_REF:0000002	KEEP AS NON CORE	Summary: InterPro IPR000842/IPR005946 (PRPP synthase signatures) mapped to magnesium ion binding. PRS3 carries the conserved divalent-cation binding site (DCbs) motif of PRPP synthases, and the reaction uses Mg-ATP, so Mg2+ binding is expected; it has not been measured directly for the PRS3 subunit. Reason: Cofactor binding inferred from the conserved DCbs motif; correct for a PRPP synthase subunit but not the core function. Supporting Evidence: PMID:9829955 contains the characteristic motifs of PRS enzymes, the divalent cation binding site (DCbs) and the PRPP binding site (PRPPbs) file:yeast/PRS3/PRS3-uniprot.txt SIMILARITY: Belongs to the ribose-phosphate pyrophosphokinase family.
GO:0002189 ribose phosphate diphosphokinase complex	IDA PMID:15280369 Heterooligomeric phosphoribosyl diphosphate synthase of Sacc...	ACCEPT	Summary: Hove-Jensen co-expressed the five yeast PRS genes in a PRPP-less E. coli strain: no single subunit had activity, while PRS3 gave active enzyme only together with Prs1, and stable enzyme required at least three subunits. This shows that PRS3 acts as a subunit of a hetero-oligomeric PRPP synthase. Supporting Evidence: PMID:15280369 Expression of the five S. cerevisiae PRS genes individually in an Escherichia coli PRPP-less strain (Deltaprs) showed that a single PRS gene product had no PRPP synthase activity. PMID:15280369 These combinations were PRS1 PRS2, PRS1 PRS3, and PRS1 PRS4, as well as PRS5 PRS2 and PRS5 PRS4. PMID:15280369 yeast PRPP synthase requires at least three different subunits to be stable in vitro
GO:0002189 ribose phosphate diphosphokinase complex	IEA GO_REF:0000117	ACCEPT	Summary: ARBA00026376 machine-learning rule assigning the ribose phosphate diphosphokinase complex. It is correct for PRS3: yeast PRPP synthase forms only as a multi-subunit Prs complex. Supporting Evidence: PMID:15280369 yeast PRPP synthase requires at least three different subunits to be stable in vitro file:yeast/PRS3/PRS3-uniprot.txt heteromultimeric complexes with other 5-phosphoribose 1-diphosphate
GO:0004749 ribose phosphate diphosphokinase activity	IEA GO_REF:0000120	ACCEPT	Summary: EC 2.7.6.1 / RHEA:15609 and the InterPro PRPP-synthase signature mapped to ribose phosphate diphosphokinase activity. PRS3 has the PRPP-binding and DCbs motifs and is one of the five yeast PRPP synthase subunits. Caveat: no single yeast Prs subunit is active alone, so 'contributes_to' (as SGD uses in its IGI rows) is the more precise qualifier. Supporting Evidence: file:yeast/PRS3/PRS3-uniprot.txt Reaction=D-ribose 5-phosphate + ATP = 5-phospho-alpha-D-ribose 1- PMID:15280369 Expression of the five S. cerevisiae PRS genes individually in an Escherichia coli PRPP-less strain (Deltaprs) showed that a single PRS gene product had no PRPP synthase activity.
GO:0004749 ribose phosphate diphosphokinase activity	IGI PMID:15280369 Heterooligomeric phosphoribosyl diphosphate synthase of Sacc...	ACCEPT	Summary: Hove-Jensen showed in E. coli that PRS3 co-expressed with PRS1 gives active PRPP synthase, while neither subunit alone does. The 'contributes_to' qualifier fits a subunit that is inactive on its own. Supporting Evidence: PMID:15280369 Expression of the five S. cerevisiae PRS genes individually in an Escherichia coli PRPP-less strain (Deltaprs) showed that a single PRS gene product had no PRPP synthase activity. PMID:15280369 These combinations were PRS1 PRS2, PRS1 PRS3, and PRS1 PRS4, as well as PRS5 PRS2 and PRS5 PRS4.
GO:0004749 ribose phosphate diphosphokinase activity	RCA GO_REF:0000123	ACCEPT	Summary: YeastPathways RCA from the superpathway of histidine, purine and pyrimidine biosynthesis (PRPP-PWY-1), assigning ribose-5-phosphate + ATP -> PRPP + AMP (EC 2.7.6.1) to PRS3. Correct for this PRPP synthase subunit. The yeast enzyme is hetero-oligomeric, so the activity belongs to Prs subunit combinations and not to PRS3 alone. Supporting Evidence: file:yeast/PRS3/PRS3-uniprot.txt Reaction=D-ribose 5-phosphate + ATP = 5-phospho-alpha-D-ribose 1- PMID:15280369 These combinations were PRS1 PRS2, PRS1 PRS3, and PRS1 PRS4, as well as PRS5 PRS2 and PRS5 PRS4.
GO:0004749 ribose phosphate diphosphokinase activity	RCA GO_REF:0000123	ACCEPT	Summary: YeastPathways RCA from PRPP biosynthesis (PWY0-662), assigning ribose-5-phosphate + ATP -> PRPP + AMP (EC 2.7.6.1) to PRS3. Correct for this PRPP synthase subunit. The yeast enzyme is hetero-oligomeric, so the activity belongs to Prs subunit combinations and not to PRS3 alone. Supporting Evidence: file:yeast/PRS3/PRS3-uniprot.txt Reaction=D-ribose 5-phosphate + ATP = 5-phospho-alpha-D-ribose 1- PMID:15280369 These combinations were PRS1 PRS2, PRS1 PRS3, and PRS1 PRS4, as well as PRS5 PRS2 and PRS5 PRS4.
GO:0005515 protein binding	IPI PMID:16429126 Proteome survey reveals modularity of the yeast cell machine...	REMOVE	Summary: PRS3-Prs1 association detected in the Gavin et al. 2006 genome-wide TAP/affinity-purification-MS complex screen. It reflects assembly of the hetero-oligomeric PRPP synthase from Prs subunits, as shown independently by two-hybrid and co-expression studies. The interaction is real, but 'protein binding' adds nothing; complex membership is already captured by GO:0002189. Reason: Uninformative 'protein binding'. The Prs-Prs subunit association is represented by part_of ribose phosphate diphosphokinase complex (GO:0002189), and no more specific MF term applies. Supporting Evidence: PMID:16429126 Here we report the first genome-wide screen for complexes in an organism, budding yeast, using affinity purification and mass spectrometry. PMID:10212224 Specifically PRS1 and PRS3 polypeptides interact strongly with each other, and there are significant interactions between the PRS5 polypeptide and either the PRS2 or PRS4 polypeptides.
GO:0005515 protein binding	IPI PMID:17892321 Structure-templated predictions of novel protein interaction...	REMOVE	Summary: PRS3-Prs1 association detected in the Betel et al. 2007 D-MIST structure-templated interaction predictions, validated by IP. It reflects assembly of the hetero-oligomeric PRPP synthase from Prs subunits, as shown independently by two-hybrid and co-expression studies. The interaction is real, but 'protein binding' adds nothing; complex membership is already captured by GO:0002189. Reason: Uninformative 'protein binding'. The Prs-Prs subunit association is represented by part_of ribose phosphate diphosphokinase complex (GO:0002189), and no more specific MF term applies. Supporting Evidence: PMID:17892321 Among the experimentally confirmed predictions were interactions between the five components of the PRS complex, which together compose the 5-phosphoribosyl-1(a)-pyrophosphate synthetase enzyme (EC number 2.7.6.1). PMID:10212224 Specifically PRS1 and PRS3 polypeptides interact strongly with each other, and there are significant interactions between the PRS5 polypeptide and either the PRS2 or PRS4 polypeptides.
GO:0005515 protein binding	IPI PMID:17892321 Structure-templated predictions of novel protein interaction...	REMOVE	Summary: PRS3-Prs4 association detected in the Betel et al. 2007 D-MIST structure-templated interaction predictions, validated by IP. It reflects assembly of the hetero-oligomeric PRPP synthase from Prs subunits, as shown independently by two-hybrid and co-expression studies. The interaction is real, but 'protein binding' adds nothing; complex membership is already captured by GO:0002189. Reason: Uninformative 'protein binding'. The Prs-Prs subunit association is represented by part_of ribose phosphate diphosphokinase complex (GO:0002189), and no more specific MF term applies. Supporting Evidence: PMID:17892321 Among the experimentally confirmed predictions were interactions between the five components of the PRS complex, which together compose the 5-phosphoribosyl-1(a)-pyrophosphate synthetase enzyme (EC number 2.7.6.1). PMID:10212224 Specifically PRS1 and PRS3 polypeptides interact strongly with each other, and there are significant interactions between the PRS5 polypeptide and either the PRS2 or PRS4 polypeptides.
GO:0005515 protein binding	IPI PMID:18467557 An in vivo map of the yeast protein interactome.	REMOVE	Summary: PRS3-Prs5 association detected in the Tarassov et al. 2008 genome-wide DHFR protein-fragment complementation (PCA) screen. It reflects assembly of the hetero-oligomeric PRPP synthase from Prs subunits, as shown independently by two-hybrid and co-expression studies. The interaction is real, but 'protein binding' adds nothing; complex membership is already captured by GO:0002189. Reason: Uninformative 'protein binding'. The Prs-Prs subunit association is represented by part_of ribose phosphate diphosphokinase complex (GO:0002189), and no more specific MF term applies. Supporting Evidence: PMID:18467557 We have performed a genome-wide in vivo screen for protein-protein interactions in Saccharomyces cerevisiae by means of a protein-fragment complementation assay (PCA). PMID:10212224 Specifically PRS1 and PRS3 polypeptides interact strongly with each other, and there are significant interactions between the PRS5 polypeptide and either the PRS2 or PRS4 polypeptides.
GO:0005515 protein binding	IPI PMID:18719252 High-quality binary protein interaction map of the yeast int...	REMOVE	Summary: PRS3-Prs1 association detected in the Yu et al. 2008 high-throughput binary yeast two-hybrid map. It reflects assembly of the hetero-oligomeric PRPP synthase from Prs subunits, as shown independently by two-hybrid and co-expression studies. The interaction is real, but 'protein binding' adds nothing; complex membership is already captured by GO:0002189. Reason: Uninformative 'protein binding'. The Prs-Prs subunit association is represented by part_of ribose phosphate diphosphokinase complex (GO:0002189), and no more specific MF term applies. Supporting Evidence: PMID:18719252 demonstrating that high-throughput yeast two-hybrid (Y2H) screening provides high-quality binary interaction information PMID:10212224 Specifically PRS1 and PRS3 polypeptides interact strongly with each other, and there are significant interactions between the PRS5 polypeptide and either the PRS2 or PRS4 polypeptides.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: PRS3-Prs1 association detected in the Michaelis et al. 2023 proteome-wide affinity-enrichment MS interactome. It reflects assembly of the hetero-oligomeric PRPP synthase from Prs subunits, as shown independently by two-hybrid and co-expression studies. The interaction is real, but 'protein binding' adds nothing; complex membership is already captured by GO:0002189. Reason: Uninformative 'protein binding'. The Prs-Prs subunit association is represented by part_of ribose phosphate diphosphokinase complex (GO:0002189), and no more specific MF term applies. Supporting Evidence: PMID:37968396 Affinity purification coupled to mass spectrometry is an ideal tool for such mapping PMID:10212224 Specifically PRS1 and PRS3 polypeptides interact strongly with each other, and there are significant interactions between the PRS5 polypeptide and either the PRS2 or PRS4 polypeptides.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: PRS3-Prs4 association detected in the Michaelis et al. 2023 proteome-wide affinity-enrichment MS interactome. It reflects assembly of the hetero-oligomeric PRPP synthase from Prs subunits, as shown independently by two-hybrid and co-expression studies. The interaction is real, but 'protein binding' adds nothing; complex membership is already captured by GO:0002189. Reason: Uninformative 'protein binding'. The Prs-Prs subunit association is represented by part_of ribose phosphate diphosphokinase complex (GO:0002189), and no more specific MF term applies. Supporting Evidence: PMID:37968396 Affinity purification coupled to mass spectrometry is an ideal tool for such mapping PMID:10212224 Specifically PRS1 and PRS3 polypeptides interact strongly with each other, and there are significant interactions between the PRS5 polypeptide and either the PRS2 or PRS4 polypeptides.
GO:0005515 protein binding	IPI PMID:37968396 The social and structural architecture of the yeast protein ...	REMOVE	Summary: PRS3-Prs5 association detected in the Michaelis et al. 2023 proteome-wide affinity-enrichment MS interactome. It reflects assembly of the hetero-oligomeric PRPP synthase from Prs subunits, as shown independently by two-hybrid and co-expression studies. The interaction is real, but 'protein binding' adds nothing; complex membership is already captured by GO:0002189. Reason: Uninformative 'protein binding'. The Prs-Prs subunit association is represented by part_of ribose phosphate diphosphokinase complex (GO:0002189), and no more specific MF term applies. Supporting Evidence: PMID:37968396 Affinity purification coupled to mass spectrometry is an ideal tool for such mapping PMID:10212224 Specifically PRS1 and PRS3 polypeptides interact strongly with each other, and there are significant interactions between the PRS5 polypeptide and either the PRS2 or PRS4 polypeptides.
GO:0005737 cytoplasm	HDA PMID:14562095 Global analysis of protein localization in budding yeast.	ACCEPT	Summary: Huh et al. genome-wide GFP-tagging localized PRS3-GFP to the cytoplasm. This is consistent with a soluble PRPP synthase subunit. Supporting Evidence: PMID:14562095 We classify these proteins, representing 75% of the yeast proteome, into 22 distinct subcellular localization categories
GO:0005737 cytoplasm	IBA GO_REF:0000033	ACCEPT	Summary: PAINT IBA (PTN000025022) placing PRPP synthases as active in the cytoplasm. Correct for PRS3, which GFP tagging places in the cytoplasm. Supporting Evidence: PMID:14562095 We classify these proteins, representing 75% of the yeast proteome, into 22 distinct subcellular localization categories
GO:0005737 cytoplasm	IEA GO_REF:0000044	ACCEPT	Summary: UniProt subcellular-location mapping (SL-0086 Cytoplasm), itself based on the Huh et al. GFP data for PRS3. Correct. Supporting Evidence: file:yeast/PRS3/PRS3-uniprot.txt SUBCELLULAR LOCATION: Cytoplasm {ECO:0000269\|PubMed:14562095}.
GO:0005829 cytosol	RCA GO_REF:0000123	ACCEPT	Summary: YeastPathways RCA (PRPP-PWY-1) placing the PRPP synthase reaction in the cytosol. This is consistent with cytoplasmic localization of PRS3-GFP and with the soluble, non-organellar nature of the PRPP synthase complex. Supporting Evidence: PMID:14562095 We classify these proteins, representing 75% of the yeast proteome, into 22 distinct subcellular localization categories file:yeast/PRS3/PRS3-uniprot.txt Reaction=D-ribose 5-phosphate + ATP = 5-phospho-alpha-D-ribose 1-
GO:0005829 cytosol	RCA GO_REF:0000123	ACCEPT	Summary: YeastPathways RCA (PWY0-662) placing the PRPP synthase reaction in the cytosol. This is consistent with cytoplasmic localization of PRS3-GFP and with the soluble, non-organellar nature of the PRPP synthase complex. Supporting Evidence: PMID:14562095 We classify these proteins, representing 75% of the yeast proteome, into 22 distinct subcellular localization categories file:yeast/PRS3/PRS3-uniprot.txt Reaction=D-ribose 5-phosphate + ATP = 5-phospho-alpha-D-ribose 1-
GO:0006015 5-phosphoribose 1-diphosphate biosynthetic process	IBA GO_REF:0000033	ACCEPT	Summary: PAINT IBA (PTN000025022) for PRPP biosynthesis; PRS3 is one of the experimentally grounded yeast donors. This is the core process. Supporting Evidence: PMID:15280369 These combinations were PRS1 PRS2, PRS1 PRS3, and PRS1 PRS4, as well as PRS5 PRS2 and PRS5 PRS4. PMID:10212224 These data suggest that yeast phosphoribosyl pyrophosphate synthetase exists in vivo as multimeric complex(es).
GO:0006015 5-phosphoribose 1-diphosphate biosynthetic process	IEA GO_REF:0000120	ACCEPT	Summary: UniPathway UPA00087 / ARBA00027291 mapping to PRPP biosynthesis (route I, step 1/1). Correct for PRS3. Supporting Evidence: file:yeast/PRS3/PRS3-uniprot.txt PATHWAY: Metabolic intermediate biosynthesis; 5-phospho-alpha-D-ribose
GO:0006015 5-phosphoribose 1-diphosphate biosynthetic process	IGI PMID:15280369 Heterooligomeric phosphoribosyl diphosphate synthase of Sacc...	ACCEPT	Summary: Co-expression of PRS3 with PRS1 in a PRPP-less E. coli prs mutant restored PRPP synthesis in growing cells, while either gene alone did not. This directly shows PRS3 taking part in PRPP biosynthesis as a subunit. Supporting Evidence: PMID:15280369 Expression of the five S. cerevisiae PRS genes individually in an Escherichia coli PRPP-less strain (Deltaprs) showed that a single PRS gene product had no PRPP synthase activity. PMID:15280369 These combinations were PRS1 PRS2, PRS1 PRS3, and PRS1 PRS4, as well as PRS5 PRS2 and PRS5 PRS4.
GO:0006015 5-phosphoribose 1-diphosphate biosynthetic process	IMP PMID:10212224 Genetic analysis and enzyme activity suggest the existence o...	ACCEPT	Summary: Hernando et al. built all combinations of prs disruptions and measured PRPP synthase activity, growth and nucleotide pools. Loss of PRS3 lowers PRPP-synthesizing capacity, and combinations with other prs nulls are lethal or slow-growing. Prs3 is, with Prs1, one of the two major subunits; prs3 nulls have reduced nucleotide pools and pleiotropic cell-integrity/actin phenotypes. Supporting Evidence: PMID:10212224 a lethal phenotype that corresponds to strains containing a double disruption in PRS2 and PRS4 in combination with a disruption in either PRS1 or PRS3 PMID:9108276 disruption of PRS1 or PRS3 has a significant effect on cell metabolism, whereas disruption of PRS2 or PRS4 has little measurable effect
GO:0006164 purine nucleotide biosynthetic process	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: PAINT IBA (PTN000025022; donors are rat Prps1/2 and human PRPS1/2) for purine nucleotide biosynthesis. PRPP made by the Prs complex is the ribose-phosphate donor for de novo and salvage purine nucleotide synthesis, so PRS3 supplies an essential precursor. In GO, PRPP biosynthesis is not part_of purine nucleotide biosynthesis, and the same PRPP also feeds pyrimidine, NAD, histidine and tryptophan synthesis. Reason: Upstream precursor supply shared by several pathways. It is acceptable, but the core process is GO:0006015. Supporting Evidence: PMID:9829955 PRPP is required for the production of purine, pyrimidine, and pyridine nucleotides and the amino acids histidine and tryptophan PMID:10514564 an enzyme which catalyses the first step in a variety of biosynthetic pathways, including purine and pyrimidine biosynthesis
GO:0009156 ribonucleoside monophosphate biosynthetic process	IEA GO_REF:0000002	KEEP AS NON CORE	Summary: InterPro IPR000842 (PRPP synthase conserved site) mapped to ribonucleoside monophosphate biosynthetic process. PRPP is the ribose-phosphate donor for phosphoribosyltransferases that make IMP, UMP and other NMPs, but PRS3 itself makes PRPP and not a nucleoside monophosphate. Reason: Indirect: describes the downstream use of PRPP. Retained as non-core. Supporting Evidence: PMID:9829955 PRPP is required for the production of purine, pyrimidine, and pyridine nucleotides and the amino acids histidine and tryptophan
GO:0009165 nucleotide biosynthetic process	IEA GO_REF:0000002	TOO GENERAL	Summary: InterPro IPR005946 (ribose-phosphate diphosphokinase) mapped to nucleotide biosynthetic process. This is correct in the broad sense that PRPP from the Prs complex is required for nucleotide synthesis; deletion of PRS1 or PRS3 lowers nucleotide pools. The step PRS3 catalyses is PRPP synthesis. Reason: Broad downstream process; the core process is PRPP biosynthesis. Supporting Evidence: PMID:9829955 PRPP is required for the production of purine, pyrimidine, and pyridine nucleotides and the amino acids histidine and tryptophan PMID:9108276 disruption of PRS1 or PRS3 has a significant effect on cell metabolism, whereas disruption of PRS2 or PRS4 has little measurable effect
GO:0009165 nucleotide biosynthetic process	RCA GO_REF:0000123	TOO GENERAL	Summary: YeastPathways RCA inherited from the superpathway PRPP-PWY-1 (histidine, purine and pyrimidine biosynthesis). PRS3 catalyses only the PRPP-forming entry step, so the superpathway BP is a generalisation; PRPP is a genuine precursor of all nucleotides. Reason: Superpathway-inherited BP. The precise process is GO:0006015 PRPP biosynthesis. Supporting Evidence: PMID:10514564 an enzyme which catalyses the first step in a variety of biosynthetic pathways, including purine and pyrimidine biosynthesis PMID:9829955 PRPP is required for the production of purine, pyrimidine, and pyridine nucleotides and the amino acids histidine and tryptophan

Gene Description

Existing Annotations Review

Core Functions

PRS3 is a subunit of the hetero-oligomeric cytosolic PRPP synthase. It contributes to ribose 5-phosphate + ATP -> PRPP + AMP but has no activity alone. The enzyme supplies PRPP for nucleotide, histidine and tryptophan synthesis.

References

Suggested Questions for Experts

Deep Research

SGD

SGD gene description for PRS3 (yeast)

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Notes

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