PF03671: Ufm1

Ubiquitin fold modifier 1 protein

Curation status: SEEDED
Seed status: EX DUF
Characterization: UNSCORED

Grounding

PF03671: Ubiquitin fold modifier 1 protein
IPR005375: integrated entry for Ubiquitin fold modifier 1 protein

Source description

This is a family of short ubiquitin-like proteins, that is like neither type-1 or type-2. It is a ubiquitin-fold modifier 1 (Ufm1) that is synthesised in a precursor form of 85 amino-acid residues. In humans the enzyme for Ufm1 is Uba5 and the conjugating enzyme is Ufc1. Prior to activation by Uba5 the extra two amino acids at the C-terminal region of the human pro-Ufm1 protein are removed to expose Gly whose residue is necessary for conjugation to target molecule(s). The mature Ufm1 is conjugated to yet unidentified endogenous proteins,[InterPro reference PUB00034740]. While Ubiquitin and many Ubls possess the conserved C-terminal di-glycine that is adenylated by each specific E1 or E1-like enzyme, respectively, in an ATP-dependent manner, Ufm1(1-83) possesses a single glycine at its C-terminus, which is followed by a Ser-Cys dipeptide in the precursor form of Ufm1. The C-terminally processed Ufm1(1-83) is specifically activated by Uba5, an E1-like enzyme, and then transferred to its cognate Ufc1, an E2-like enzyme [InterPro reference PUB00034738].

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

5 verified sequence examples. FASTA

UniProt	Protein / organism	Sequence	Provenance
A8DYH2	Ubiquitin-fold modifier 1 Drosophila melanogaster	87 aa; version 1 UniProt 2026_03	UNIPROT FETCH 2 sibling references ProteinTraitsMech: CDD:cd01766 ProteinTraitsMech: Pfam:PF03671
P34661	Ubiquitin-fold modifier 1 Caenorhabditis elegans	94 aa; version 1 UniProt 2026_03	UNIPROT FETCH 2 sibling references ProteinTraitsMech: CDD:cd01766 ProteinTraitsMech: Pfam:PF03671
P61960	Ubiquitin-fold modifier 1 Homo sapiens	85 aa; version 1 UniProt 2026_03	PTM REGISTRY MIRROR 4 sibling references ProteinTraitsMech: GO:1990592 ProteinTraitsMech: CDD:cd01766 ProteinTraitsMech: Pfam:PF03671 ProteinTraitsMech: UniProtKB:P61960
P61961	Ubiquitin-fold modifier 1 Mus musculus	85 aa; version 1 UniProt 2026_03	UNIPROT FETCH 2 sibling references ProteinTraitsMech: CDD:cd01766 ProteinTraitsMech: Pfam:PF03671
Q9CA23	Ubiquitin-fold modifier 1 Arabidopsis thaliana	93 aa; version 1 UniProt 2026_03	UNIPROT FETCH 2 sibling references ProteinTraitsMech: CDD:cd01766 ProteinTraitsMech: Pfam:PF03671

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: 1,961
matches: 1,977
proteomes: 1,382
taxa: 4,552
structures: 18
alphafold models: 1,706
domain architectures: 36

Classification basis

pfam previous unknown name

No scoring reasons supplied.

Related Mech records

This family joined the worklist after the frozen cross-Mech scan, so other Mechs were not searched for it. Missing links here are not evidence that other Mechs lack it; rows shown come from mentions of a former DUF/UPF name.

No cross-Mech examples are present in the supplied snapshot.

Curation history and reviews

No retained curation events supplied.

No retained review supplied.

Record source

data/families/PF03671.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.