All families / PF01641
PF01641: SelR
SelR domain
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF01641: SelR domain
IPR002579: integrated entry for SelR domain
Source description
Methionine sulfoxide reduction is an important process, by which cells regulate biological processes and cope with oxidative stress. MsrA, a protein involved in the reduction of methionine sulfoxides in proteins, has been known for four decades and has been extensively characterised with respect to structure and function. However, recent studies revealed that MsrA is only specific for methionine-S-sulfoxides. Because oxidised methionines occur in a mixture of R and S isomers in vivo, it was unclear how stereo-specific MsrA could be responsible for the reduction of all protein methionine sulfoxides. It appears that a second methionine sulfoxide reductase, SelR, evolved that is specific for methionine-R-sulfoxides, the activity that is different but complementary to that of MsrA. Thus, these proteins, working together, could reduce both stereoisomers of methionine sulfoxide. This domain is found both in SelR proteins and fused with the peptide methionine sulfoxide reductase enzymatic domain PF01625 (Pfam entry). The domain has two conserved cysteines and histidines. The domain binds both selenium and zinc [InterPro reference PUB00020323]. The final cysteine is found to be replaced by the rare amino acid selenocysteine in some members of the family [InterPro reference PUB00006463]. This family has methionine-R-sulfoxide reductase activity [InterPro reference PUB00020323].
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
14 verified sequence examples. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| O49707 | Peptide methionine sulfoxide reductase B8 Arabidopsis thaliana | 143 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| P0A746 | Peptide methionine sulfoxide reductase MsrB Escherichia coli (strain K12) | 137 aa; version 1 UniProt 2026_03 | PTM REGISTRY MIRROR10 sibling references
|
| P54155 | Peptide methionine sulfoxide reductase MsrB Bacillus subtilis (strain 168) | 143 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q78J03 | Methionine-R-sulfoxide reductase B2, mitochondrial Mus musculus | 175 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q84JT6 | Peptide methionine sulfoxide reductase B9 Arabidopsis thaliana | 143 aa; version 1 UniProt 2026_03 | PTM REGISTRY MIRROR |
| Q8BU85 | Methionine-R-sulfoxide reductase B3, mitochondrial Mus musculus | 253 aa; version 2 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q8INK9 | Methionine-R-sulfoxide reductase B1 Drosophila melanogaster | 208 aa; version 3 UniProt 2026_03 | UNIPROT FETCH |
| Q8IXL7 | Methionine-R-sulfoxide reductase B3 Homo sapiens | 192 aa; version 2 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q8VY86 | Peptide methionine sulfoxide reductase B7 Arabidopsis thaliana | 144 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
| Q9C5C8 | Peptide methionine sulfoxide reductase B2, chloroplastic Arabidopsis thaliana | 202 aa; version 1 UniProt 2026_03 | UNIPROT FETCH |
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
- 30,911
- matches
- 30,990
- proteomes
- 19,951
- taxa
- 31,866
- structures
- 22
- alphafold models
- 21,713
- domain architectures
- 157
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.