All families / PF20173

PF20173: ZnF_RZ-type

RZ type zinc finger domain

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

Grounding

PF20173: RZ type zinc finger domain
IPR046439: integrated entry for RZ type zinc finger domain

Source description

This entry represents the RZ type zinc finger domain, found in NFX1-type zinc finger-containing protein 1 (ZNFX1) and E3 ubiquitin-protein ligase RNF213 from humans. It contains two conserved histidine residues and four conserved cysteine residues in a CHC3H motif. It can bind divalent transition metals, with a preference for Zn2+. ZNFX1 is an RNA-binding protein that initiates the antiviral response and is required to restrict the replication of RNA viruses [InterPro reference PUB00100916,InterPro reference PUB00100918]. RNF213 is a giant E3 ubiquitin ligase that can catalyse ubiquitination of both proteins and lipids, which is involved in various processes, such as lipid metabolism, angiogenesis and cell-autonomous immunity. It functions as a key immune sensor by catalysing ubiquitination of the lipid A moiety of bacterial LPS via its RZ-type zinc-finger and restricts the proliferation of cytosolic bacteria [InterPro reference PUB00100919,InterPro reference PUB00100915]. RNF213 is a major susceptibility factor of Moyamoya disease [InterPro reference PUB00100917].

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

4 verified sequence examples. FASTA

UniProt	Protein / organism	Sequence	Provenance
E9Q555	E3 ubiquitin-protein ligase RNF213 Mus musculus	5148 aa; version 3 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF20173
Q63HN8	E3 ubiquitin-protein ligase RNF213 Homo sapiens	5207 aa; version 3 UniProt 2026_03	PTM REGISTRY MIRROR 2 sibling references ProteinTraitsMech: Pfam:PF20173 ProteinTraitsMech: UniProtKB:Q63HN8
Q8R151	NFX1-type zinc finger-containing protein 1 Mus musculus	1909 aa; version 3 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF20173
Q9P2E3	NFX1-type zinc finger-containing protein 1 Homo sapiens	1918 aa; version 2 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF20173

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: 4,869
matches: 4,880
proteomes: 2,015
taxa: 5,628
structures: 11
alphafold models: 895
domain architectures: 272

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/PF20173.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.