PTS

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0003874 6-pyruvoyltetrahydropterin synthase activity	IBA GO_REF:0000033	ACCEPT	Summary: PTPS catalytic activity is the core molecular function of this enzyme, well-supported by phylogenetic analysis (IBA) from PANTHER family PTN000287347 which includes orthologs from mouse, rat, C. elegans, and Dictyostelium. This is consistent with the deep research review describing PTPS as a Zn2+-dependent lyase that converts 7,8-dihydroneopterin triphosphate to 6-pyruvoyl-5,6,7,8-tetrahydropterin (Werner et al. 2011). Reason: The IBA annotation correctly captures the core enzymatic function of PTPS. This activity is extensively documented in biochemical literature and represents the defining function of the enzyme. UniProt confirms EC 4.2.3.12 classification and the catalytic activity details. Supporting Evidence: file:human/PTS/PTS-deep-research-falcon.md
GO:0006729 tetrahydrobiopterin biosynthetic process	IBA GO_REF:0000033	ACCEPT	Summary: PTPS involvement in BH4 biosynthesis is well-established through phylogenetic analysis. The enzyme catalyzes the second step in the de novo BH4 biosynthetic pathway (GCH1 -> PTS -> SPR), providing BH4 as an essential cofactor for aromatic amino acid hydroxylases and nitric oxide synthases (Werner et al. 2011). Reason: This annotation correctly identifies the core biological process for PTPS. BH4 biosynthesis is the primary pathway in which PTPS functions, and deficiency causes BH4-deficient hyperphenylalaninemia (OMIM 261640). Supporting Evidence: file:human/PTS/PTS-deep-research-falcon.md PTPS is the middle enzyme in de novo BH4 biosynthesis (GCH1→PTS→SPR)
GO:0005739 mitochondrion	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: The mitochondrial localization is supported by IBA from phylogenetic analysis. However, the primary localization literature describes PTPS as a soluble cytosolic enzyme. The deep research review states PTPS is a "soluble cytosolic enzyme functioning within the cytosolic de novo BH4 synthesis machinery." Some mitochondrial localization may exist but cytosol is the primary site. Reason: While there is evidence for mitochondrial localization (also supported by IDA from LIFEdb), the primary functional localization of PTPS is cytosolic where BH4 biosynthesis occurs. Mitochondrial localization may represent secondary localization or experimental detection but is not the primary site of function. Supporting Evidence: file:human/PTS/PTS-deep-research-falcon.md Cellular localization: PTPS is a soluble cytosolic enzyme functioning within the cytosolic de novo BH4 synthesis machinery
GO:0003874 6-pyruvoyltetrahydropterin synthase activity	IEA GO_REF:0000120	ACCEPT	Summary: IEA annotation based on combined automated methods including ARBA rules, mouse ortholog transfer, InterPro domain annotations (IPR022469, IPR022470), and EC number mapping. This is consistent with the IBA annotation and experimental evidence. Reason: The annotation is consistent with the core enzymatic function of PTPS and supported by multiple independent computational methods.
GO:0006729 tetrahydrobiopterin biosynthetic process	IEA GO_REF:0000120	ACCEPT	Summary: IEA annotation based on InterPro domain annotations and UniPathway pathway mapping (UPA00849). Consistent with the IBA annotation and established pathway knowledge. Reason: The annotation correctly identifies the biological process in which PTPS functions.
GO:0016829 lyase activity	IEA GO_REF:0000043	ACCEPT	Summary: PTPS is classified as a lyase (EC 4.2.3.12). The annotation is derived from UniProtKB keyword mapping. This is a parent term of the more specific GO:0003874. Reason: While GO:0003874 (6-pyruvoyltetrahydropterin synthase activity) is more specific and preferred, this broader classification is accurate. PTPS is indeed a lyase that catalyzes elimination of triphosphate from DHNTP.
GO:0046872 metal ion binding	IEA GO_REF:0000043	MODIFY	Summary: PTPS requires Zn2+ for catalytic activity (one Zn2+ ion per subunit). This is documented in UniProt cofactor annotation and the Reactome entry. However, this is a very general term. Reason: The term is too general. PTPS specifically binds zinc ions (Zn2+) as a catalytic cofactor. A more informative term would be zinc ion binding (GO:0008270). Proposed replacements: zinc ion binding Supporting Evidence: file:human/PTS/PTS-deep-research-falcon.md Human PTPS possesses a Zn2+-containing catalytic site located in a ~12 Å cavity Reactome:R-HSA-1474184 has a requirement for Zn2+ (one Zn2+ ion bound per subunit) and Mg2+ ions for activity
GO:0005515 protein binding	IPI PMID:19060904 An empirical framework for binary interactome mapping.	MARK AS OVER ANNOTATED	Summary: High-throughput interactome mapping study. The protein binding term is uninformative; the specific interactors detected (FXR2, NTAQ1) in this screen do not have clear functional relevance to PTPS core function. Reason: Generic protein binding terms from high-throughput interactome screens are uninformative. The biologically meaningful protein interactions for PTPS are with itself (homohexamer formation) and possibly regulatory kinases, not these interactors from binary screens. Supporting Evidence: PMID:19060904 An empirical framework for binary interactome mapping.
GO:0005515 protein binding	IPI PMID:25416956 A proteome-scale map of the human interactome network.	MARK AS OVER ANNOTATED	Summary: Proteome-scale interactome mapping study (HI-II-14). Detected interactions with SDCBP, COIL, LNX1, THAP10. These are not known to be functionally relevant to PTPS enzymatic activity or BH4 biosynthesis. Reason: High-throughput binary interactome data. The generic protein binding term does not add informative annotation about PTPS function. Supporting Evidence: PMID:25416956 A proteome-scale map of the human interactome network.
GO:0005515 protein binding	IPI PMID:27107014 An inter-species protein-protein interaction network across ...	MARK AS OVER ANNOTATED	Summary: Inter-species protein-protein interaction network study. Detected interactions are cross-species and do not represent physiologically relevant interactions for human PTPS. Reason: Cross-species interactome data. Generic protein binding annotation is not informative for understanding PTPS function. Supporting Evidence: PMID:27107014 An inter-species protein-protein interaction network across vast evolutionary distance.
GO:0005515 protein binding	IPI PMID:31515488 Extensive disruption of protein interactions by genetic vari...	MARK AS OVER ANNOTATED	Summary: Study on disruption of protein interactions by genetic variants. Detected interactions with FXR2, NTAQ1, SDCBP. These overlap with other high-throughput screens but lack functional validation. Reason: High-throughput variant effect mapping. The protein binding term is too generic to be informative. Supporting Evidence: PMID:31515488 Extensive disruption of protein interactions by genetic variants across the allele frequency spectrum in human populations.
GO:0005515 protein binding	IPI PMID:32296183 A reference map of the human binary protein interactome.	MARK AS OVER ANNOTATED	Summary: Reference binary interactome map (HuRI). Detected interactions with AP2M1 and DDIT4L. Reason: High-throughput interactome mapping. Generic protein binding is uninformative for PTPS function annotation. Supporting Evidence: PMID:32296183 Apr 8. A reference map of the human binary protein interactome.
GO:0042802 identical protein binding	IPI PMID:16169070 A human protein-protein interaction network: a resource for ...	ACCEPT	Summary: PTPS forms a functional homohexamer (two trimers in head-to-head fashion). Self-interaction is required for proper enzyme assembly and activity. Active sites are located at subunit interfaces. Reason: Homohexamer formation is functionally essential for PTPS. The enzyme cannot function as a monomer; the active site requires residues from adjacent subunits (intersubunit Cys-Asp-His catalytic triad). This self-interaction is biologically meaningful. Supporting Evidence: file:human/PTS/PTS-deep-research-falcon.md PTPS assembles as a homohexamer (two trimers, head-to-head). Each of six active centers lies at subunit interfaces PMID:16169070 A human protein-protein interaction network: a resource for annotating the proteome.
GO:0042802 identical protein binding	IPI PMID:16189514 Towards a proteome-scale map of the human protein-protein in...	ACCEPT	Summary: Independent confirmation of PTPS self-interaction consistent with homohexamer formation. Reason: Supports the essential oligomerization of PTPS for enzymatic function. Supporting Evidence: PMID:16189514 Towards a proteome-scale map of the human protein-protein interaction network.
GO:0042802 identical protein binding	IPI PMID:21516116 Next-generation sequencing to generate interactome datasets.	ACCEPT	Summary: Next-generation sequencing interactome study confirming PTPS self-interaction. Reason: Consistent with known homohexameric structure of PTPS. Supporting Evidence: PMID:21516116 Next-generation sequencing to generate interactome datasets.
GO:0042802 identical protein binding	IPI PMID:24599843 Elucidating common structural features of human pathogenic v...	ACCEPT	Summary: Study on structural features of pathogenic mutations. PTPS self-interaction is confirmed. Importantly, this study relates interface residue mutations to pathogenicity, supporting the functional importance of hexamer assembly. Reason: This annotation is supported by structural evidence that mutations affecting hexamer interface cause disease (PTPS deficiency). Supporting Evidence: file:human/PTS/PTS-deep-research-falcon.md interface residues critical for hexamer stability and variant pathogenicity interpretation PMID:24599843 Elucidating common structural features of human pathogenic variations using large-scale atomic-resolution protein networks.
GO:0042802 identical protein binding	IPI PMID:25416956 A proteome-scale map of the human interactome network.	ACCEPT	Summary: Proteome-scale interactome map confirming PTPS homodimerization/hexamerization. Reason: Consistent with essential homohexamer formation. Supporting Evidence: PMID:25416956 A proteome-scale map of the human interactome network.
GO:0042802 identical protein binding	IPI PMID:25502805 A massively parallel pipeline to clone DNA variants and exam...	ACCEPT	Summary: Massively parallel pipeline study confirming PTPS self-interaction. Reason: Multiple independent studies confirm PTPS homooligomerization. Supporting Evidence: PMID:25502805 eCollection 2014 Dec.
GO:0042802 identical protein binding	IPI PMID:25910212 Widespread macromolecular interaction perturbations in human...	ACCEPT	Summary: Study on macromolecular interaction perturbations in genetic disorders confirming PTPS self-interaction. Relevant to understanding how mutations disrupt hexamer formation. Reason: Supports the functional importance of PTPS oligomerization. Supporting Evidence: PMID:25910212 Widespread macromolecular interaction perturbations in human genetic disorders.
GO:0042802 identical protein binding	IPI PMID:31515488 Extensive disruption of protein interactions by genetic vari...	ACCEPT	Summary: Variant effect study confirming PTPS self-interaction and examining how variants affect it. Reason: Further validates the essential nature of PTPS homooligomerization. Supporting Evidence: PMID:31515488 Extensive disruption of protein interactions by genetic variants across the allele frequency spectrum in human populations.
GO:0042802 identical protein binding	IPI PMID:32296183 A reference map of the human binary protein interactome.	ACCEPT	Summary: Reference binary interactome map confirming PTPS self-interaction. Reason: Consistent with known hexameric structure. Supporting Evidence: PMID:32296183 Apr 8. A reference map of the human binary protein interactome.
GO:0005829 cytosol	IEA GO_REF:0000107	ACCEPT	Summary: Transfer from mouse ortholog (Ensembl Compara). Cytosolic localization is the primary functional location for PTPS where BH4 biosynthesis occurs. Reason: Cytosolic localization is well-established and represents the functional location of PTPS. Supporting Evidence: file:human/PTS/PTS-deep-research-falcon.md PTPS is a soluble cytosolic enzyme functioning within the cytosolic de novo BH4 synthesis machinery
GO:0042802 identical protein binding	IEA GO_REF:0000107	ACCEPT	Summary: Inferred from mouse ortholog. Consistent with the multiple IPI annotations for self-interaction. Reason: Consistent with essential homohexamer formation.
GO:0046146 tetrahydrobiopterin metabolic process	IEA GO_REF:0000107	ACCEPT	Summary: Transfer from mouse ortholog. This is a parent term of GO:0006729 (tetrahydrobiopterin biosynthetic process) which is more specific. Reason: While the more specific term GO:0006729 is preferred, this broader annotation is not incorrect. PTPS is involved in BH4 metabolism via its biosynthetic role.
GO:0005829 cytosol	TAS Reactome:R-HSA-1475422	ACCEPT	Summary: Reactome annotation based on the PTPS phosphorylation reaction occurring in the cytosol. Reason: Consistent with the established cytosolic localization of PTPS. Supporting Evidence: Reactome:R-HSA-1475422
GO:0005829 cytosol	TAS Reactome:R-HSA-1474184	ACCEPT	Summary: Reactome annotation for the PTPS catalytic reaction occurring in cytosol. Reason: Consistent with cytosolic BH4 biosynthesis. Supporting Evidence: Reactome:R-HSA-1474184
GO:0005737 cytoplasm	IDA GO_REF:0000054	ACCEPT	Summary: LIFEdb localization study using expressed fusion proteins. Cytoplasm is consistent with cytosol localization (cytosol is a part of cytoplasm). Reason: Consistent with the established cytosolic localization of PTPS. Cytoplasm is a valid broader term.
GO:0005739 mitochondrion	IDA GO_REF:0000054	KEEP AS NON CORE	Summary: LIFEdb localization study detected mitochondrial localization. This may represent partial localization or an artifact, as the primary functional location is cytosol. Reason: While mitochondrial localization is detected in this fusion protein study, the primary functional site for PTPS in BH4 biosynthesis is the cytosol. This may represent secondary localization.
GO:0003874 6-pyruvoyltetrahydropterin synthase activity	TAS PMID:3308682 Hyperphenylalaninemia due to deficiency of 6-pyruvoyl tetrah...	ACCEPT	Summary: This annotation references a 1987 clinical study of PTPS deficiency that established the enzymatic defect in patients with hyperphenylalaninemia due to biopterin synthesis deficiency. The paper characterized erythrocyte PTS activity and demonstrated "less than 10% of normal" activity in affected individuals. Reason: The study provides clinical evidence supporting PTPS as the deficient enzyme in this form of hyperphenylalaninemia, confirming the enzymatic function. Supporting Evidence: PMID:3308682 The deficient enzyme in these subjects is 6-pyruvoyl tetrahydropterin synthase (PTS). Erythrocyte activity of PTS in homozygotes (or compound heterozygotes) is less than 10% of normal.
GO:0006520 amino acid metabolic process	TAS PMID:3308682 Hyperphenylalaninemia due to deficiency of 6-pyruvoyl tetrah...	KEEP AS NON CORE	Summary: PTPS deficiency leads to impaired phenylalanine metabolism (hyperphenylalaninemia) because BH4 is required as a cofactor for phenylalanine hydroxylase (PAH). However, PTPS itself does not directly metabolize amino acids - it produces the BH4 cofactor. Reason: While PTPS deficiency affects amino acid metabolism (especially phenylalanine via PAH), this is an indirect effect. The primary function is BH4 biosynthesis. The term is not wrong but represents downstream physiological consequences rather than the direct biological process of PTPS. Supporting Evidence: PMID:3308682 We have identified deficient biopterin synthesis in four probands and one sib with persistent postnatal hyperphenylalaninemia.
GO:0006729 tetrahydrobiopterin biosynthetic process	TAS PMID:3308682 Hyperphenylalaninemia due to deficiency of 6-pyruvoyl tetrah...	ACCEPT	Summary: The study demonstrates that PTPS deficiency causes impaired biopterin synthesis. Patients had deficient biopterin synthesis and treatment with oral tetrahydropterin restored function. Reason: The clinical study provides evidence that PTPS is essential for BH4 (biopterin) biosynthesis. Supporting Evidence: PMID:3308682 We have identified deficient biopterin synthesis in four probands and one sib with persistent postnatal hyperphenylalaninemia.
GO:0007417 central nervous system development	TAS PMID:3308682 Hyperphenylalaninemia due to deficiency of 6-pyruvoyl tetrah...	KEEP AS NON CORE	Summary: PTPS deficiency leads to impaired CNS development due to deficiency of neurotransmitters (dopamine, serotonin) that require BH4 as a cofactor for their biosynthesis. The paper notes "Impaired development was apparent at 3 months in one proband not treated early" and that treatment "maintained or improved CNS function." Reason: While PTPS deficiency clearly affects CNS development, this is an indirect downstream effect of impaired neurotransmitter biosynthesis due to BH4 deficiency. PTPS itself is not directly involved in CNS developmental processes; rather, its product BH4 is required for tyrosine hydroxylase (dopamine) and tryptophan hydroxylase (serotonin). This is a pleiotropic disease phenotype rather than a core function. Supporting Evidence: PMID:3308682 Impaired development was apparent at 3 months in one proband not treated early. Treatment with oral tetrahydropterin restored adequate phenylalanine hydroxylase activity; it also maintained or improved CNS function.

Gene Description

Existing Annotations Review

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References

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Deep Research

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