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Protein / target

Phenylalanine-4-hydroxylase

Encoded byPAHP00439Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
2
Approved medicines
Open Targets target-level
Small-molecule tractable
Druggability
Approved Drug
1
Research papers

Protein at a glance

Biological role

Phenylalanine 4-monooxygenase

Strongest disease association

Phenylketonurias

Via encoding gene PAH · Genetic evidence · score 0.99

Therapeutic position

Established drug target

Small molecules

Research activity

Emerging research

1 papers · latest 2023

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function overview

Catalyzes the hydroxylation of L-phenylalanine to L-tyrosine

Domains and Gene Ontology detail (8)

Domains & features

ACT

Gene Ontology

  • Ccytosol
  • Firon ion binding
  • Fphenylalanine 4-monooxygenase activity
  • Pamino acid biosynthetic process
  • Pcatecholamine biosynthetic process
  • PL-phenylalanine catabolic process
  • PL-tyrosine biosynthetic process

452 aa · 52 kDa

Translational evidence

Open Targets 26

Why this target matters therapeutically, strongest evidence first. Disease associations are gene-level (via the gene that encodes this protein) and open into the full confidence synthesis; the development universe, tractability and safety annotations are target-level, from Open Targets.

Strongest disease associations · via encoding gene PAH

Gene-level evidence surfaced through the gene PAH that encodes this protein — not a direct protein–disease relationship. Ranked by Forefront's causal-directness weighting, so genetically- and clinically-evidenced diseases lead over ones that merely share the literature.

Phenylketonurias
1.00Well supported

Genetic evidence dominant · Open Targets 0.89

Genetic Diseases, Inborn
0.91Well supported

Genetic evidence dominant · Open Targets 0.55

Malnutrition
0.46Limited support

Clinical evidence dominant · Open Targets 0.37

View evidence synthesis (3)
PhenylketonuriasWell supported
1.00
agreement 0.911.00
Genetic45%Clinical32%Pathway11%Animal model9%Literature3%Genetic literaturedup

Open Targets aggregate 0.89 · 5 independent evidence families · 1 not counted as duplicate

Genetic Diseases, InbornWell supported
0.91
agreement 0.771.00
Genetic99%Literature2%

Open Targets aggregate 0.55 · 2 independent evidence families

MalnutritionLimited support
0.46
agreement 0.300.61
Clinical100%Literature0%

Open Targets aggregate 0.37 · 2 independent evidence families

The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the per-type scores above show the calculation.

Show all associations
Phenylketonurias0.89
Genetic Diseases, Inborn0.55
Malnutrition0.37

Drug development

2 compounds recorded · 2 approved

Open Targets' development universe — every compound recorded against the target at any stage, not all approved medicines.

View all recorded compounds (2)
SAPROPTERIN DIHYDROCHLORIDEApproval
SAPROPTERINApproval

Open Targets known-drugs universe. Drug name and highest clinical stage only — the disease relationship is NOT read from this slice (it carries trial-context noise); approved indications come from the canonical graph above.

Tractability

Small moleculesStrong

Approved Drug and Structure with Ligand support this modality.

Protein degradersEmerging

Feasibility evidence (half-life data and small molecule binder) — no clinical-stage drug of this modality recorded.

View underlying tractability evidence (6)
SM · Approved DrugSM · Structure with LigandSM · High-Quality PocketSM · Druggable FamilyPR · Half-life DataPR · Small Molecule Binder

Raw Open Targets tractability assessment buckets, by modality.

Research activity

1 papers · to 2023

Papers linked directly to this protein. This is the protein's own literature — descriptor-derived papers are kept separate below.

Most cited

Recent

Europe PMC papers linked directly to this protein.