All families / PF00902
PF00902: TatC
Sec-independent protein translocase protein (TatC)
- Curation status
- SEEDED
- Seed status
- EX DUF
- Characterization
- UNSCORED
Grounding
PF00902: Sec-independent protein translocase protein (TatC)
IPR002033: integrated entry for Sec-independent protein translocase protein (TatC)
Source description
The bacterial Tat system has a remarkable ability to transport folded proteins even enzyme complexes across the cytoplasmic membrane. It is structurally and mechanistically similar to the Delta pH-driven thylakoidal protein import pathway. A functional Tat system or Delta pH-dependent pathway requires three integral membrane proteins: TatA/Tha4, TatB/Hcf106 and TatC/cpTatC. The TatC protein is essential for the function of both pathways. It might be involved in twin-arginine signal peptide recognition, protein translocation and proton translocation. Sequence analysis predicts that TatC contains six transmembrane helices (TMHs), and experimental data confirmed that N- and C-termini of TatC or cpTatC are exposed to the cytoplasmic or stromal face of the membrane. The cytoplasmic N-terminus and the first cytoplasmic loop region of the Escherichia coli TatC protein are essential for protein export. At least two TatC molecules co-exist within each Tat translocon [InterPro reference PUB00011123].
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
7 verified sequence examples. FASTA
| UniProt | Protein / organism | Sequence | Provenance |
|---|---|---|---|
| O05523 | Sec-independent protein translocase protein TatCy Bacillus subtilis (strain 168) | 254 aa; version 1 UniProt 2026_03 | PTM REGISTRY MIRROR |
| P42252 | Sec-independent protein translocase protein TatCd Bacillus subtilis (strain 168) | 242 aa; version 4 UniProt 2026_03 | UNIPROT FETCH |
| P69423 | Sec-independent protein translocase protein TatC Escherichia coli (strain K12) | 258 aa; version 2 UniProt 2026_03 | PTM REGISTRY MIRROR10 sibling references
|
| P93312 | Uncharacterized tatC-like protein ymf16 Arabidopsis thaliana | 280 aa; version 3 UniProt 2026_03 | UNIPROT FETCH2 sibling references |
| Q94G17 | Sec-independent protein translocase protein TATC, chloroplastic Pisum sativum | 353 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q9AVE6 | Sec-independent protein translocase protein TATC, chloroplastic Oryza sativa subsp. japonica | 359 aa; version 1 UniProt 2026_03 | UNIPROT FETCH1 sibling references |
| Q9SJV5 | Sec-independent protein translocase protein TATC, chloroplastic Arabidopsis thaliana | 340 aa; version 2 UniProt 2026_03 | UNIPROT FETCH |
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
- 18,890
- matches
- 19,252
- proteomes
- 16,293
- taxa
- 23,768
- structures
- 11
- alphafold models
- 12,534
- domain architectures
- 28
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.