GO:0016714 oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen: Mechanism, Genes and Research Methods
Research-grade guide for scientists and biopharma professionals
Key Takeaways
• GO:0016714 describes a molecular function in which reduced pteridine serves as one electron donor and a second donor is oxidized, with one atom of molecular oxygen incorporated into the product.
• This activity is best known for aromatic amino acid hydroxylases such as phenylalanine hydroxylase (PAH), tyrosine hydroxylase (TH), and tryptophan hydroxylase (TPH1/TPH2), which require tetrahydrobiopterin (BH4) as the reduced pteridine donor.
• The catalytic cycle couples pterin oxidation to substrate hydroxylation and often involves a non-heme mononuclear iron center and a pterin-4a-carbinolamine intermediate.
• Loss of PAH activity causes phenylketonuria (PKU), a classic inborn error of metabolism, making GO:0016714 directly relevant to human disease.
• Genome-wide association and functional enrichment studies in livestock have linked this activity to gastrointestinal nematode resistance and conception rate, showing its broader biological importance.
• CRISPR-based knockout, point-mutation, knock-in, and overexpression models allow causal testing of GO:0016714 enzymes in disease and metabolic pathways.
Description
GO:0016714 is a Gene Ontology molecular_function term defined as catalysis of an oxidation-reduction reaction in which hydrogen or electrons are transferred from reduced pteridine and one other donor, and one atom of oxygen is incorporated into one donor. In practical terms, this describes enzymes that use a reduced pteridine cofactor, most commonly tetrahydrobiopterin (BH4), to activate molecular oxygen and hydroxylate a second substrate. The term captures a distinctive catalytic strategy: the pteridine is consumed as a donor while the second substrate receives one oxygen atom from O2. This activity is central to aromatic amino acid metabolism and neurotransmitter biosynthesis, and it is therefore a recurring focus in studies of inherited metabolic disease, neurobiology, and animal production traits. Because the reaction requires both a reduced pteridine and a second donor, GO:0016714 is mechanistically distinct from other monooxygenase activities that use flavin or heme cofactors without a pteridine donor. Researchers annotate genes to this term when biochemical evidence shows pteridine-dependent oxygen incorporation, and such annotations are used in enrichment analyses to connect genomic signals to metabolic pathways.
oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen At A Glance
| GO ID | GO:0016714 |
|---|---|
| GO term | oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen |
| Ontology | molecular_function |
| Synonym | none listed in QuickGO |
| Major function | Pteridine-dependent monooxygenation, typically using tetrahydrobiopterin (BH4) as the reduced pteridine donor and incorporating one oxygen atom into a second substrate |
| Cofactor | Reduced pteridine, commonly BH4; many enzymes also require non-heme Fe(II) |
| Representative enzymes | Phenylalanine hydroxylase (PAH), tyrosine hydroxylase (TH), tryptophan hydroxylase 1/2 (TPH1/TPH2) |
| Pathway context | Aromatic amino acid hydroxylation and neurotransmitter biosynthesis |
| Disease relevance | Phenylketonuria and related metabolic disorders |
What Is GO:0016714?
In your own words, GO:0016714 describes an oxidoreductase activity that acts on paired donors: one donor is reduced pteridine, and the other donor is the substrate that becomes hydroxylated. During the reaction, molecular oxygen is reduced and one atom of oxygen is incorporated into the second donor, while the pteridine is oxidized. This is a pteridine-dependent monooxygenase activity, and it is defined by the cofactor requirement and the oxygen-incorporation chemistry rather than by a single gene family.
Why Is oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen Important in Cell Biology?
GO:0016714 matters because it defines a catalytic activity that controls the availability of aromatic amino acids and neurotransmitters, and because its dysfunction is directly linked to human inherited metabolic disease. The term is also used in functional enrichment analyses to interpret genomic and transcriptomic data, including studies of parasite resistance and fertility traits in livestock. Understanding this activity therefore spans clinical genetics, neurochemistry, and agricultural genomics.
• It defines the BH4-dependent hydroxylation chemistry used by aromatic amino acid hydroxylases.
• It is essential for phenylalanine catabolism, and its loss causes phenylketonuria.
• It contributes to dopamine and serotonin biosynthesis through TH and TPH enzymes.
• It provides a mechanistic framework for interpreting variants in metabolic disease genes.
• It is used in functional enrichment of GWAS signals for complex traits such as nematode resistance.
• It is relevant to fertility and reproduction traits in cattle through enrichment analyses.
• It helps distinguish pteridine-dependent monooxygenases from other oxidoreductases.
• It supports the design of CRISPR models to test enzyme function causally.
What Happens During oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen?
Reduced pteridine binding and activation
In simple terms: The enzyme first grabs its pteridine helper molecule.
The reaction begins when the enzyme binds a reduced pteridine, most commonly tetrahydrobiopterin (BH4), in the active site. This binding positions the pteridine for electron transfer and primes the enzyme for oxygen activation. In aromatic amino acid hydroxylases, the pteridine site is adjacent to the substrate site and the non-heme iron center, allowing coordinated chemistry.
Oxygen activation and substrate hydroxylation
In simple terms: Oxygen is split, and one oxygen atom is added to the substrate.
Molecular oxygen is reduced at the active site, and one atom of oxygen is incorporated into the second donor, which is typically an aromatic amino acid. The other oxygen atom is reduced to water. This step requires the reduced pteridine as the electron donor and often involves a non-heme Fe(II) center that helps activate O2.
Pteridine oxidation and product release
In simple terms: The pteridine is used up, and the hydroxylated product leaves.
As the substrate is hydroxylated, the pteridine is oxidized, forming a pterin-4a-carbinolamine intermediate that is subsequently dehydrated and reduced back to BH4 by auxiliary enzymes. The hydroxylated product is released, completing the catalytic cycle. This coupling of pteridine oxidation to substrate hydroxylation is the defining feature of GO:0016714.
Cofactor regeneration and pathway integration
In simple terms: The cell recycles the pteridine so the enzyme can work again.
Because BH4 is consumed stoichiometrically, cells regenerate it through pterin-4a-carbinolamine dehydratase and dihydropteridine reductase. This regeneration links GO:0016714 activity to broader metabolic networks, including folate and biopterin metabolism. Defects in regeneration can phenocopy enzyme deficiency and are relevant to disease.
Key Genes Involved in GO:0016714 oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen
The genes below encode enzymes or cofactor-related proteins that carry out or support GO:0016714 activity, based on published biochemical and genetic evidence.
| Gene | Major Role | Research Relevance |
|---|---|---|
| PAH | Phenylalanine hydroxylase; converts phenylalanine to tyrosine using BH4 | Loss-of-function causes phenylketonuria; model for metabolic disease |
| TH | Tyrosine hydroxylase; rate-limiting enzyme in dopamine biosynthesis | Studied in Parkinson's disease and catecholamine disorders |
| TPH1 | Tryptophan hydroxylase 1; peripheral serotonin synthesis | Investigated in gastrointestinal and metabolic biology |
| TPH2 | Tryptophan hydroxylase 2; neuronal serotonin synthesis | Studied in mood disorders and neurodevelopment |
| GCH1 | GTP cyclohydrolase 1; rate-limiting BH4 biosynthesis | Mutations cause BH4 deficiency and dystonia |
| PTS | 6-pyruvoyltetrahydropterin synthase; BH4 biosynthesis | Defects cause atypical PKU and neurotransmitter deficiency |
| SPR | Sepiapterin reductase; BH4 biosynthesis | Linked to BH4 deficiency and neurological disease |
| QDPR | Dihydropteridine reductase; regenerates BH4 | Defects cause hyperphenylalaninemia |
| PCBD1 | Pterin-4a-carbinolamine dehydratase; BH4 regeneration | Associated with hyperphenylalaninemia |
| DNAJC12 | Chaperone for aromatic amino acid hydroxylases | Mutations cause BH4-responsive neurotransmitter disorders |
| PAH | Aromatic amino acid hydroxylase family member | Target for CRISPR knockout and knock-in disease models |
| TH | Catecholamine biosynthesis | Target for point-mutation studies of enzyme activity |
| TPH2 | Serotonin biosynthesis | Target for overexpression and behavioral studies |
| GCH1 | BH4 synthesis | Target for knock-in models of dystonia |
| SPR | BH4 synthesis | Target for metabolic rescue experiments |
| QDPR | BH4 regeneration | Target for knockout studies of hyperphenylalaninemia |
| PCBD1 | BH4 regeneration | Target for biochemical assays |
How Is oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen Regulated?
GO:0016714 activity is regulated at multiple levels. Enzyme abundance and stability are influenced by chaperones such as DNAJC12, which supports aromatic amino acid hydroxylases. Cofactor availability is controlled by BH4 biosynthetic enzymes (GCH1, PTS, SPR) and regeneration enzymes (QDPR, PCBD1), so changes in their expression directly affect flux through this activity. In addition, post-translational modifications and feedback inhibition by substrate or product analogs can modulate enzyme output, as seen for PAH and TH. These regulatory layers make GO:0016714 a sensitive node in metabolic and neurotransmitter pathways.
oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen and Human Disease
| Gene | Disease / Biology | Potential Experimental Model |
|---|---|---|
| PAH | Phenylketonuria; hyperphenylalaninemia | CRISPR knockout or point-mutation knock-in in hepatocyte-like cells |
| GCH1 | BH4 deficiency; dystonia | Knock-in of patient variants in iPSC-derived neurons |
| TH | Dopamine-related movement disorder | Overexpression and knockout in neuronal cell lines |
| QDPR | Hyperphenylalaninemia; BH4 regeneration defect | Knockout in hepatic cell models |
| DNAJC12 | Neurotransmitter deficiency | Knockout and rescue with wild-type chaperone |
Phenylketonuria and hyperphenylalaninemia
Biallelic loss-of-function variants in PAH cause phenylketonuria, the most common inborn error of amino acid metabolism, and impaired GO:0016714 activity leads to phenylalanine accumulation and neurotoxicity if untreated. Defects in BH4 biosynthesis or regeneration genes such as GCH1, PTS, SPR, QDPR, and PCBD1 also reduce this activity and cause hyperphenylalaninemia, often with additional neurological features.
Neurotransmitter disorders and movement disease
Because TH and TPH enzymes use BH4-dependent hydroxylation, reduced GO:0016714 activity can impair dopamine and serotonin synthesis. This contributes to movement disorders, dystonia, and neuropsychiatric phenotypes observed in BH4 deficiency syndromes. DNAJC12 mutations further illustrate how chaperone loss can destabilize these enzymes and produce neurotransmitter deficiency.
Complex trait genetics and animal models
Functional enrichment analyses in livestock have associated GO:0016714 with gastrointestinal nematode resistance in sheep and with conception rate in crossbred beef heifers, indicating that this activity may influence immune and reproductive traits. These findings highlight the value of this term in genome-wide association follow-up and in comparative biology.
From oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen-Related Genes to Experimental Models
| Research Question | Suitable Model |
|---|---|
| Does loss of PAH reduce GO:0016714 activity? | PAH knockout cell line |
| Does a patient variant alter enzyme kinetics? | Point-mutation knock-in of the variant |
| Can wild-type enzyme rescue the phenotype? | Knock-in of wild-type cDNA or overexpression |
| Where is the enzyme localized in cells? | Tagged knock-in with fluorescent or epitope tag |
| Does BH4 regeneration affect flux? | Knockout of QDPR or PCBD1 |
| Can candidate genes be screened at scale? | CRISPR library screening in relevant cell models |
How to Study the oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen Process
| Method | What It Measures | Typical Application |
|---|---|---|
| HPLC-based hydroxylation assay | Substrate conversion and product formation | Confirming enzyme activity in vitro |
| RNA-seq | Transcript abundance and pathway enrichment | Identifying GO:0016714 genes in disease datasets |
| Functional enrichment analysis | Overrepresentation of GO terms | GWAS and transcriptome follow-up |
| Affinity proteomics | Protein interactions and complexes | Finding chaperones and regulators |
| Metabolite profiling | Amino acid and neurotransmitter levels | Assessing pathway flux in cells |
| CRISPR knockout screening | Gene essentiality and pathway dependence | Discovering modifiers of GO:0016714 |
| Western blot | Protein expression and stability | Validating knockout or overexpression |
| Immunofluorescence | Subcellular localization | Studying tagged knock-in lines |
Enzymatic activity assays
Direct measurement of GO:0016714 activity uses substrate hydroxylation assays with reduced pteridine and monitoring of product formation, often by HPLC or mass spectrometry. These assays are essential to confirm that a candidate gene encodes a pteridine-dependent monooxygenase.
Genomic and transcriptomic profiling
RNA-seq and functional enrichment analyses can identify GO:0016714 as an overrepresented term in disease or trait datasets, as shown in livestock GWAS follow-up studies. Such analyses help prioritize candidate genes for experimental validation.
Proteomics and interactomics
Affinity purification and mass spectrometry can identify interaction partners and chaperones such as DNAJC12 that support GO:0016714 enzymes. These approaches reveal assembly and regulatory complexes.
Metabolite profiling
Quantification of phenylalanine, tyrosine, dopamine, and serotonin metabolites provides a functional readout of pathway flux through GO:0016714. This is particularly useful in cell models of metabolic disease.
How CRISPR Can Be Used to Study GO:0016714 oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen
Knockout
CRISPR knockout of PAH, TH, TPH, or BH4 pathway genes can eliminate GO:0016714 activity and reveal downstream metabolic consequences. These models are useful for studying phenylketonuria and neurotransmitter deficiency in relevant cell types.
Point Mutation
Point-mutation knock-in allows precise testing of patient variants in GO:0016714 enzymes, distinguishing loss-of-function from benign polymorphisms. This is especially valuable for PAH and GCH1 variant interpretation.
Knock-in
Knock-in of wild-type or tagged cDNAs can rescue knockout phenotypes and enable localization or interaction studies. Tagged knock-in lines support imaging and proteomic workflows for GO:0016714 enzymes.
Overexpression
Overexpression of GO:0016714 enzymes or BH4 biosynthetic genes can increase pathway flux and test sufficiency in cellular models. This approach is useful for studying neurotransmitter synthesis and metabolic rescue.
How EDITGENE Supports oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen Research
Researchers studying oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen-related genes often need to determine whether a candidate gene is causally involved in a metabolic or disease phenotype. EDITGENE provides the CRISPR tools and cell models needed to move from correlation to causation.
Contact EDITGENE today to design your custom CRISPR model for oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen research.
Frequently Asked Questions About oxidoreductase activity, acting on paired donors, with incorporation or reduction of molecular oxygen, reduced pteridine as one donor, and incorporation of one atom of oxygen
What is GO:0016714?
GO:0016714 is a Gene Ontology molecular_function term for oxidoreductase activity that uses reduced pteridine as one donor and incorporates one atom of oxygen into a second donor.
What enzymes carry out GO:0016714 activity?
Aromatic amino acid hydroxylases such as PAH, TH, TPH1, and TPH2 are classic examples, and they require tetrahydrobiopterin as the reduced pteridine donor.
What cofactor is required for GO:0016714?
Reduced pteridine, most commonly tetrahydrobiopterin (BH4), is required, and many enzymes also use non-heme Fe(II).
What genes are involved in GO:0016714?
PAH, TH, TPH1, TPH2, GCH1, PTS, SPR, QDPR, PCBD1, and DNAJC12 are among the genes linked to this activity.
How is GO:0016714 related to phenylketonuria?
Loss of PAH activity, a GO:0016714 enzyme, causes phenylketonuria and hyperphenylalaninemia.
Is GO:0016714 involved in neurotransmitter synthesis?
Yes, TH and TPH enzymes use this activity to synthesize dopamine and serotonin precursors.
How can I study GO:0016714 in the lab?
Enzymatic assays, RNA-seq, proteomics, metabolite profiling, and CRISPR models are commonly used.
What CRISPR models are useful for GO:0016714?
Knockout, point-mutation knock-in, tagged knock-in, and overexpression models are all suitable.
Does GO:0016714 appear in GWAS enrichment studies?
Yes, it has been reported in functional enrichment analyses for nematode resistance and conception rate traits.
Why is GO:0016714 important for disease research?
It connects pteridine-dependent hydroxylation to inherited metabolic disease and neurotransmitter disorders.
Conclusion
GO:0016714 defines a pteridine-dependent monooxygenase activity that is central to aromatic amino acid metabolism and neurotransmitter biosynthesis. Its dysfunction causes phenylketonuria and related disorders, and it appears in functional enrichment studies of complex traits. CRISPR-based models provide a direct route to test causality and to develop new therapeutic hypotheses for this activity.
References
- 1. Stafuzza NB et al.. 2023. Weighted single-step genome-wide association study and functional enrichment analyses for gastrointestinal nematode resistance traits in Santa Ines sheep.. Vet Parasitol 323:110047 PMID: 37857178
- 3. Oliver KF et al.. 2020. Loci associated with conception rate in crossbred beef heifers.. PLoS One 15(4):e0230422 PMID: 32271764
