All families / PF05003
PF05003: DUF668
Protein of unknown function (DUF668)
- Curation status
- SEEDED
- Seed status
- UNKNOWN CANDIDATE
- Characterization
- UNSCORED
Grounding
PF05003: Protein of unknown function (DUF668)
IPR007700: integrated entry for Protein of unknown function (DUF668)
Source description
This entry represents the C-terminal domain of PSI proteins from Arabidopsis. This domain is found associated with PF11961 (Domain of unknown function (DUF3475)). PSI1 was identified as a gene that is co-expressed with the phytosulfokine (PSK) receptor genes PSKR1 and PSKR2 in Arabidopsis thaliana. PSI proteins are plant-specific and promote growth [InterPro reference PUB00093967].
Evidence and references
- InterPro entry and its literature references. PUB identifiers are internal InterPro references, not PubMed identifiers. Unresolved citations link to the originating entry.
- Frozen description source: InterPro/Pfam API
Source descriptions and links are provenance, not independent functional validation.
Evidence counts: not scored.
Curated functional assertions
No curated functional assertions supplied.
Protein sequence examples
3 verified sequence examples. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| P0DO24 | Protein PSK SIMULATOR 3 Arabidopsis thaliana | 649 aa; version 1 UniProt 2026_03 | PTM REGISTRY MIRROR |
| Q9SA91 | Protein PSK SIMULATOR 2 Arabidopsis thaliana | 615 aa; version 2 UniProt 2026_03 | UNIPROT FETCH |
| Q9XID5 | Protein PSK SIMULATOR 1 Arabidopsis thaliana | 657 aa; version 2 UniProt 2026_03 | UNIPROT FETCH |
Pfam membership is not functional evidence. Whole-protein sequences do not establish domain boundaries. A coverage gap here is not absence from UniProt.
Sequences and metadata: UniProt Consortium, CC BY 4.0.
Domain matches
No residue-level domain match evidence is available in this build. Structure and AlphaFold counters do not supply coordinates or establish function.
Snapshot counters
- proteins
- 5,432
- matches
- 5,441
- proteomes
- 380
- taxa
- 1,049
- structures
- 0
- alphafold models
- 4,386
- domain architectures
- 66
Classification basis
short name matches duf; name says unknown function
No scoring reasons supplied.
Related Mech records
| Family | Mech | Record | Protein | Link basis |
|---|---|---|---|---|
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function DUF3475 | P0DO24 Protein PSK SIMULATOR 3 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function DUF3475 | Q9SA91 Protein PSK SIMULATOR 2 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function DUF3475 | Q9XID5 Protein PSK SIMULATOR 1 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function DUF668 | P0DO24 Protein PSK SIMULATOR 3 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function DUF668 | Q9SA91 Protein PSK SIMULATOR 2 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function DUF668 | Q9XID5 Protein PSK SIMULATOR 1 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function DUF668 | trait identifier | |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function (DUF3475) | P0DO24 Protein PSK SIMULATOR 3 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function (DUF3475) | Q9SA91 Protein PSK SIMULATOR 2 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Domain of unknown function (DUF3475) | Q9XID5 Protein PSK SIMULATOR 1 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Protein of unknown function (DUF668) | P0DO24 Protein PSK SIMULATOR 3 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Protein of unknown function (DUF668) | Q9SA91 Protein PSK SIMULATOR 2 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Protein of unknown function (DUF668) | Q9XID5 Protein PSK SIMULATOR 1 | canonical example family classification |
| DUF668 (PF05003) | ProteinTraitsMech | Protein of unknown function (DUF668) | trait identifier |
Curation history and reviews
No retained curation events supplied.
No retained review supplied.
Record source
Status and evidence
- Seed status
- A name-based classification of frozen InterPro/Pfam metadata. UNKNOWN CANDIDATE means the metadata explicitly says the function is unknown. KNOWN HISTORICAL DUF means a DUF name matched without that wording; this heuristic is not proof of a known function and does not establish experimental characterization. EX DUF means Pfam renamed the family away from a DUF/UPF name, as recorded in Pfam's previous identifiers; a rename usually follows published work on some members but is naming history, not proof of function for every member. Some EX DUF families' current names or descriptions still say the function is unknown; their classification basis lists this, and scoring does not treat them as characterized. FALSE POSITIVE TEXT HIT means the naming rules did not match.
- Characterization
- A separate evidence-scoring result. UNSCORED means no score has been calculated; it is not evidence that the family lacks a known function. Missing scores are not negative evidence. PARTIALLY CHARACTERIZED has partial support; KNOWN HISTORICAL DUF can inherit the seed label or reflect a known-function signal. Neither label implies experimental validation.
- Evidence counts
- Source-specific signals, not unique proteins, publications, or confidence scores. Known counts Rhea reactions and experimentally supported GO molecular-function annotations. Partial counts functional/domain assignments. Context counts structural, environmental, orthology, interaction and neighborhood signals; context alone does not assign function. Repeated annotations may not be independent.
- Curation status
- Reported separately from seed classification and characterization. SNAPSHOT ONLY means no curated metadata was supplied for this build. SEEDED denotes a source-derived record, not an expert-reviewed functional claim.
- Missing counts
- Not available means the source did not supply that counter. A zero is a reported count. Not scored means evidence counts are unavailable.