All families / PF01535
PF01535: PPR
PPR repeat
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF01535: PPR repeat
IPR002885: integrated entry for PPR repeat
Source description
This repeat has no known function. It is about 35 amino acids long and found in up to 18 copies in some proteins. This family appears to be greatly expanded in plants. This repeat occurs in PET309 P32522 (UniProtKB protein) that may be involved in RNA stabilisation [InterPro reference PUB00001271]. This domain occurs in crp1 that is involved in RNA processing [InterPro reference PUB00001258]. This repeat is associated with a predicted plant protein O49549 (UniProtKB protein) that has a domain organisation similar to the human BRCA1 protein. The repeat has been called PPR [InterPro reference PUB00017589].
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
55 verified sequence examples. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| A8MQA3 | Pentatricopeptide repeat-containing protein At4g21065 Arabidopsis thaliana | 595 aa; version 2 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| B3H672 | Pentatricopeptide repeat-containing protein At4g17616 Arabidopsis thaliana | 674 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| O04647 | Pentatricopeptide repeat-containing protein At5g27270 Arabidopsis thaliana | 1038 aa; version 2 UniProt 2026_03 | PTM REGISTRY MIRROR |
| O22137 | Pentatricopeptide repeat-containing protein At2g45350, chloroplastic Arabidopsis thaliana | 613 aa; version 2 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| O80488 | Pentatricopeptide repeat-containing protein At1g09190 Arabidopsis thaliana | 484 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| O82178 | Pentatricopeptide repeat-containing protein At2g35130 Arabidopsis thaliana | 591 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| P0C7R4 | Pentatricopeptide repeat-containing protein At1g69290 Arabidopsis thaliana | 658 aa; version 1 UniProt 2026_03 | UNIPROT FETCH2 sibling references |
| P0C8Q6 | Putative pentatricopeptide repeat-containing protein At5g08310, mitochondrial Arabidopsis thaliana | 832 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| P42704 | Leucine-rich PPR motif-containing protein, mitochondrial Homo sapiens | 1394 aa; version 3 UniProt 2026_03 | PTM REGISTRY MIRROR11 sibling references
|
| Q0WNP3 | Pentatricopeptide repeat-containing protein At4g18520, chloroplastic Arabidopsis thaliana | 617 aa; version 1 UniProt 2026_03 | PTM REGISTRY MIRROR |
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
- 228,033
- matches
- 700,640
- proteomes
- 3,274
- taxa
- 9,110
- structures
- 30
- alphafold models
- 180,864
- domain architectures
- 35,610
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.