PF03006: HlyIII

Haemolysin-III related

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

Grounding

PF03006: Haemolysin-III related
IPR004254: integrated entry for Haemolysin-III related

Source description

Members of this family are integral membrane proteins. This family includes a protein with hemolytic activity from Bacillus cereus [InterPro reference PUB00019707]. It has been proposed that YOL002c encodes a Saccharomyces cerevisiae protein that plays a key role in metabolic pathways that regulate lipid and phosphate metabolism [InterPro reference PUB00019708]. In eukaryotes, members are seven-transmembrane pass molecules found to encode functional receptors with a broad range of apparent ligand specificities, including progestin and adipoQ receptors, and hence have been named PAQR proteins [InterPro reference PUB00071573]. The mammalian members include progesterone binding proteins [InterPro reference PUB00071574]. Unlike the case with GPCR receptor proteins, the evolutionary ancestry of the members of this family can be traced back to the Archaea. This family belongs to the CREST superfamily [InterPro reference PUB00085069], which are distantly related to GPCRs.

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

15 verified sequence examples. FASTA

UniProt	Protein / organism	Sequence	Provenance
P54175	Hemolysin-3 homolog Bacillus subtilis (strain 168)	213 aa; version 1 UniProt 2026_03	UNIPROT FETCH 2 sibling references ProteinTraitsMech: NCBIfam:TIGR01065 ProteinTraitsMech: NCBIfam:NF011669
P67153	UPF0073 inner membrane protein YqfA Escherichia coli (strain K12)	219 aa; version 1 UniProt 2026_03	UNIPROT FETCH 2 sibling references ProteinTraitsMech: NCBIfam:TIGR01065 ProteinTraitsMech: NCBIfam:NF011669
Q15546	Monocyte to macrophage differentiation factor Homo sapiens	238 aa; version 2 UniProt 2026_03	UNIPROT FETCH 2 sibling references ProteinTraitsMech: NCBIfam:TIGR01065 ProteinTraitsMech: NCBIfam:NF011669
Q6TCG8	Progestin and adipoQ receptor family member 3 Mus musculus	311 aa; version 1 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: GO:2000640
Q6TCH4	Membrane progestin receptor delta Homo sapiens	344 aa; version 2 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: Pfam:PF03006
Q6TCH7	Progestin and adipoQ receptor family member 3 Homo sapiens	311 aa; version 2 UniProt 2026_03	PTM REGISTRY MIRROR 3 sibling references ProteinTraitsMech: GO:2000640 ProteinTraitsMech: Pfam:PF03006 ProteinTraitsMech: UniProtKB:Q6TCH7
Q86V24	Adiponectin receptor protein 2 Homo sapiens	386 aa; version 1 UniProt 2026_03	UNIPROT FETCH 3 sibling references ProteinTraitsMech: GO:0097003 ProteinTraitsMech: GO:0055100 ProteinTraitsMech: Pfam:PF03006
Q8BQS5	Adiponectin receptor protein 2 Mus musculus	386 aa; version 2 UniProt 2026_03	UNIPROT FETCH 7 sibling references ProteinTraitsMech: GO:0097003 ProteinTraitsMech: GO:0055100 ProteinTraitsMech: GO:0033211 ProteinTraitsMech: GO:0019395 ProteinTraitsMech: GO:0061871 ProteinTraitsMech: GO:0014075 ProteinTraitsMech: GO:0061042
Q8N4S7	Progestin and adipoQ receptor family member 4 Homo sapiens	273 aa; version 3 UniProt 2026_03	UNIPROT FETCH 1 sibling references ProteinTraitsMech: GO:2000303
Q8R189	Monocyte to macrophage differentiation factor 2 Mus musculus	247 aa; version 1 UniProt 2026_03	UNIPROT FETCH 2 sibling references ProteinTraitsMech: NCBIfam:TIGR01065 ProteinTraitsMech: NCBIfam:NF011669

First 10 shown; the FASTA and family JSON contain all examples.

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: 35,375
matches: 35,934
proteomes: 15,659
taxa: 25,660
structures: 11
alphafold models: 27,402
domain architectures: 242

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/PF03006.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.