All families / PF01930
PF01930: Cas_Cas4
Domain of unknown function DUF83
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF01930: Domain of unknown function DUF83
IPR022765: integrated entry for Domain of unknown function DUF83
Source description
This domain has no known function. The domain contains three conserved cysteines at its C terminus.
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
4 verified sequence examples. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| A3MTK6 | CRISPR-associated exonuclease Cas4 Pyrobaculum calidifontis (strain DSM 21063 / JCM 11548 / VA1) | 213 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q1CW50 | CRISPR-associated exonuclease Cas4/endonuclease Cas1 fusion Myxococcus xanthus (strain DK1622) | 568 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q57822 | CRISPR-associated exonuclease Cas4 Methanocaldococcus jannaschii (strain ATCC 43067 / DSM 2661 / JAL-1 / JCM 10045 / NBRC 100440) | 170 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| Q74H36 | CRISPR-associated exonuclease Cas4/endonuclease Cas1 fusion Geobacter sulfurreducens (strain ATCC 51573 / DSM 12127 / PCA) | 559 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 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
- 4,690
- matches
- 4,700
- proteomes
- 3,965
- taxa
- 8,240
- structures
- 10
- alphafold models
- 3,004
- domain architectures
- 45
Classification basis
name matches duf; name says unknown function; domain of unknown function; pfam previous unknown name
No scoring reasons supplied.
Related Mech records
| Family | Mech | Record | Protein | Link basis |
|---|---|---|---|---|
| Cas_Cas4 (PF01930) | ProteinTraitsMech | single-stranded DNA 5'-3' DNA exonuclease activity | Q57822 CRISPR-associated exonuclease Cas4 | canonical example family classification |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | CRISPR-associated protein Cas4 | Q57822 CRISPR-associated exonuclease Cas4 | canonical example family classification |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | Dna2/Cas4, domain of unknown function DUF83 | Q57822 CRISPR-associated exonuclease Cas4 | canonical example family classification |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | Dna2/Cas4, domain of unknown function DUF83 | trait identifier | |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | Domain of unknown function DUF83 | A3MTK6 CRISPR-associated exonuclease Cas4 | canonical example family classification |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | Domain of unknown function DUF83 | Q1CW50 CRISPR-associated exonuclease Cas4/endonuclease Cas1 fusion | canonical example family classification |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | Domain of unknown function DUF83 | Q74H36 CRISPR-associated exonuclease Cas4/endonuclease Cas1 fusion | canonical example family classification |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | Domain of unknown function DUF83 | trait identifier | |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | PD-(D/E)XK endonuclease-like domain superfamily | Q57822 CRISPR-associated exonuclease Cas4 | canonical example family classification |
| Cas_Cas4 (PF01930) | ProteinTraitsMech | CATH homologous superfamily 3.90.320.10 | Q57822 CRISPR-associated exonuclease Cas4 | canonical example family classification |
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.