DUFMech

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

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

UniProtProtein / organismSequenceProvenance
P0DO24Protein PSK SIMULATOR 3
Arabidopsis thaliana
649 aa; version 1
UniProt 2026_03
PTM REGISTRY MIRROR
5 sibling references
Q9SA91Protein PSK SIMULATOR 2
Arabidopsis thaliana
615 aa; version 2
UniProt 2026_03
UNIPROT FETCH
4 sibling references
Q9XID5Protein PSK SIMULATOR 1
Arabidopsis thaliana
657 aa; version 2
UniProt 2026_03
UNIPROT FETCH
4 sibling references

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

FamilyMechRecordProteinLink basis
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function DUF3475P0DO24
Protein PSK SIMULATOR 3
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function DUF3475Q9SA91
Protein PSK SIMULATOR 2
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function DUF3475Q9XID5
Protein PSK SIMULATOR 1
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function DUF668P0DO24
Protein PSK SIMULATOR 3
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function DUF668Q9SA91
Protein PSK SIMULATOR 2
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function DUF668Q9XID5
Protein PSK SIMULATOR 1
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function DUF668
trait identifier
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function (DUF3475)P0DO24
Protein PSK SIMULATOR 3
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function (DUF3475)Q9SA91
Protein PSK SIMULATOR 2
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechDomain of unknown function (DUF3475)Q9XID5
Protein PSK SIMULATOR 1
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechProtein of unknown function (DUF668)P0DO24
Protein PSK SIMULATOR 3
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechProtein of unknown function (DUF668)Q9SA91
Protein PSK SIMULATOR 2
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechProtein of unknown function (DUF668)Q9XID5
Protein PSK SIMULATOR 1
canonical example family classification
DUF668 (PF05003)ProteinTraitsMechProtein of unknown function (DUF668)
trait identifier

Curation history and reviews

No retained curation events supplied.

No retained review supplied.

Record source

data/families/PF05003.yaml
Family YAML in this build

Download this family (JSON)

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.