All families / PF01883
PF01883: FeS_assembly_P
Iron-sulfur cluster assembly protein
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF01883: Iron-sulfur cluster assembly protein
IPR002744: integrated entry for Iron-sulfur cluster assembly protein
Source description
This family has an alpha/beta topology, with 13 conserved hydrophobic residues at its core and a putative active site containing a highly conserved cysteine [InterPro reference PUB00037899]. Members of this family are involved in a range of physiological functions. The family includes PaaJ (PhaH) O84984 (UniProtKB protein) from Pseudomonas putida. PaaJ forms a complex with PaaG (PhaF) O84982 (UniProtKB protein), PaaI (PhaG) O84983 (UniProtKB protein) and PaaK (PhaI) O84985 (UniProtKB protein), which hydroxylates phenylacetic acid to 2-hydroxyphenylacetic acid [InterPro reference PUB00005820]. It also includes PaaD P76080 (UniProtKB protein) from Escherichia coli, a member of a multicomponent oxygenase involved in phenylacetyl-CoA hydroxylation [InterPro reference PUB00010200]. Furthermore, several members of this family are shown to be involved in iron-sulfur (FeS) cluster assembly. Iron-sulfur (FeS) clusters are inorganic co-factors that are are able to transfer electrons and act as catalysts [InterPro reference PUB00095787]. They are involved in diverse cellular processes including cellular respiration, DNA replication and repair, antibiotic resistance, and dinitrogen fixation [InterPro reference PUB00085141]. The biogenesis of such clusters from elemental iron and sulfur is an enzymatic process that requires a set of specialised proteins. Proteins containing this domain include the chloroplast protein HCF101 (high chlorophyll fluorescence 101), Q6STH5 (UniProtKB protein), which has been described as an essential and specific factor for assembly of [4Fe-4S]-cluster-containing protein complexes such as the membrane complex Photosystem I (PSI) and the heterodimeric FTR (ferredoxin-thioredoxin reductase) complex [InterPro reference PUB00095787] and is involved in the assembly of [4Fe-4S] clusters and their transfer to apoproteins [InterPro reference PUB00095787]. The mature HCF101 protein contains this domain at the N-terminal as well as eight cysteine residues along the sequence. All cysteine residues are conserved among higher plants, but of the two cysteine residues located in this domain only Cys128 is highly conserved and is present in the highly conserved P-loop domain of the plant HCF101 (CKGGVGKS) [InterPro reference PUB00095787]. SufT protein from Staphylococcus aureus is composed of this domain solely and is shown to be involved in the maturation of FeS proteins [InterPro reference PUB00085141]. Given all this data, it is hypothesised that this domain might play a role in FeS cluster assembly.
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
11 verified sequence examples. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| P38829 | MIP18 family protein YHR122W Saccharomyces cerevisiae (strain ATCC 204508 / S288c) | 231 aa; version 1 UniProt 2026_03 | UNIPROT FETCH2 sibling references |
| P76080 | Putative 1,2-phenylacetyl-CoA epoxidase, subunit D Escherichia coli (strain K12) | 165 aa; version 2 UniProt 2026_03 | PTM REGISTRY MIRROR |
| Q6STH5 | Fe-S cluster assembly factor HCF101, chloroplastic Arabidopsis thaliana | 532 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| Q9C9G6 | Protein AE7 Arabidopsis thaliana | 157 aa; version 2 UniProt 2026_03 | PTM REGISTRY MIRROR10 sibling references
|
| Q9D187 | Cytosolic iron-sulfur assembly component 2B Mus musculus | 163 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| Q9DCL2 | Cytosolic iron-sulfur assembly component 2A Mus musculus | 160 aa; version 1 UniProt 2026_03 | UNIPROT FETCH2 sibling references |
| Q9H5X1 | Cytosolic iron-sulfur assembly component 2A Homo sapiens | 160 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| Q9SR25 | Protein AE7-like 2 Arabidopsis thaliana | 149 aa; version 2 UniProt 2026_03 | UNIPROT FETCH2 sibling references |
| Q9V968 | MIP18 family protein galla-1 Drosophila melanogaster | 218 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q9VTC4 | MIP18 family protein galla-2 Drosophila melanogaster | 156 aa; version 1 UniProt 2026_03 | UNIPROT FETCH2 sibling references |
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
- 37,284
- matches
- 37,296
- proteomes
- 17,779
- taxa
- 28,426
- structures
- 15
- alphafold models
- 24,936
- domain architectures
- 120
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
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.