PF18141: UPF1_1B_dom

RNA helicase UPF1, 1B domain

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

Grounding

PF18141: RNA helicase UPF1, 1B domain
IPR040812: integrated entry for RNA helicase UPF1, 1B domain

Source description

UPF1 (or regulator of nonsense transcripts 1 homologue) is an essential RNA helicase that detects mRNAs containing premature stop codons and triggers their degradation. Together with UPF2 and UPF3, forms a surveillance complex, in which UPF2 acts as a bridge between UPF1 and UPF3. UPF2 and UPF3 are non-enzymatic components of the complex that stimulate the activity of UPF1 [InterPro reference PUB00050141,InterPro reference PUB00095891]. UPF1 has a N-terminal cysteine/histidine-rich zinc-binding domain (CH/ZBD), a regulatory 1B domain, followed by a helicase core that belongs to superfamily 1 (SF1). This entry represents 1B domain of UPF1 which has a regulatory role. It suffers conformational changes from an inhibitory state to a transition-state complex that modulate RNA binding [InterPro reference PUB00050141,InterPro reference PUB00095891].

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

6 verified sequence examples. FASTA

UniProt	Protein / organism	Sequence	Provenance
O76512	Regulator of nonsense transcripts 1 Caenorhabditis elegans	1069 aa; version 1 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF18141
P30771	ATP-dependent helicase NAM7 Saccharomyces cerevisiae (strain ATCC 204508 / S288c)	971 aa; version 1 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF18141
Q92900	Regulator of nonsense transcripts 1 Homo sapiens	1129 aa; version 2 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF18141
Q9EPU0	Regulator of nonsense transcripts 1 Mus musculus	1124 aa; version 2 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF18141
Q9FJR0	Regulator of nonsense transcripts 1 homolog Arabidopsis thaliana	1254 aa; version 2 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF18141
Q9VYS3	Regulator of nonsense transcripts 1 homolog Drosophila melanogaster	1180 aa; version 2 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF18141

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: 3,779
matches: 3,790
proteomes: 2,612
taxa: 7,201
structures: 12
alphafold models: 3,031
domain architectures: 89

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/PF18141.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.