All families / PF09418
PF09418: DUF2009
Non-canonical E2 ubiquitin-conjugating enzyme, DUF2009 family
- Curation status
- SEEDED
- Seed status
- KNOWN HISTORICAL DUF
- Characterization
- UNSCORED
Grounding
PF09418: Non-canonical E2 ubiquitin-conjugating enzyme, DUF2009 family
IPR057668: integrated entry for Non-canonical E2 ubiquitin-conjugating enzyme, DUF2009 family
Source description
This entry represents a novel family of non-canonical E2 ubiquitin-conjugating enzymes that lack the typical HPN motif found in other E2 enzymes. The domain contains a highly conserved catalytic cysteine (C572 in PF3D7_0811400) that forms a thioester bond with ubiquitin. This was experimentally validated through mutational analysis and biochemical assays [InterPro reference PUB00160741]. The domain is found in the C-terminal region of proteins, while the N-terminal region contains coiled helices involved in protein-protein interactions with other ubiquitin pathway components like Rbx1. The domain represents a new class of E2 enzymes particularly found in Apicomplexan parasites.
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 |
|---|---|---|---|
| Q10301 | UPF0652 protein C22H10.08 Schizosaccharomyces pombe (strain 972 / ATCC 24843) | 492 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q54BM8 | UPF0652 protein Dictyostelium discoideum | 677 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q9USN2 | UPF0652 protein C16A11.03c Schizosaccharomyces pombe (strain 972 / ATCC 24843) | 466 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
- 924
- matches
- 1,077
- proteomes
- 659
- taxa
- 1,643
- structures
- 0
- alphafold models
- 769
- domain architectures
- 37
Classification basis
short name matches duf
No scoring reasons supplied.
Related Mech records
| Family | Mech | Record | Protein | Link basis |
|---|---|---|---|---|
| DUF2009 (PF09418) | ProteinTraitsMech | Non-canonical E2 ubiquitin-conjugating enzyme, C-terminal | trait identifier | |
| DUF2009 (PF09418) | ProteinTraitsMech | Non-canonical E2 ubiquitin-conjugating enzyme, DUF2009 family | Q10301 UPF0652 protein C22H10.08 | canonical example family classification |
| DUF2009 (PF09418) | ProteinTraitsMech | Non-canonical E2 ubiquitin-conjugating enzyme, DUF2009 family | Q54BM8 UPF0652 protein | canonical example family classification |
| DUF2009 (PF09418) | ProteinTraitsMech | Non-canonical E2 ubiquitin-conjugating enzyme, DUF2009 family | Q9USN2 UPF0652 protein C16A11.03c | canonical example family classification |
| DUF2009 (PF09418) | ProteinTraitsMech | Non-canonical E2 ubiquitin-conjugating enzyme, DUF2009 family | 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.