TatC (PA5070) is the polytopic inner-membrane core subunit of the twin-arginine translocation (Tat) system of Pseudomonas aeruginosa. With six transmembrane helices, it forms, together with TatB, the receptor complex that recognises the twin-arginine motif of Tat signal peptides; substrate binding then recruits TatA to form the active translocon, which moves fully folded proteins across the cytoplasmic membrane using the proton motive force. In P. aeruginosa the Tat pathway exports many periplasmic and secreted proteins, among them the pyoverdine-biogenesis protein PvdN, so tat mutants fail to make pyoverdine.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: UniProt/UniRule subcellular-location mapping. TatC is a multi-pass inner (plasma) membrane protein. Reason: Correct location; TatC spans the cytoplasmic membrane. Supporting Evidence: file:PSEAE/tatC/tatC-uniprot.txt Cell inner membrane |
| GO:0008320 transmembrane protein transporter activity | IEA GO_REF:0000104 | TOO GENERAL | Summary: UniRule mapping of transmembrane protein transporter activity, the generic transporter MF for the Tat receptor. Reason: Entailed by the accepted GO:0009977, which is_a this term and names the proton-motive-force-driven mechanism. |
| GO:0008320 transmembrane protein transporter activity | IMP PMID:16621825 Pyoverdine-mediated iron uptake in Pseudomonas aeruginosa: t... | TOO GENERAL | Summary: PseudoCAP row from the tat-pathway paper. The transporter activity claim is correct for the Tat receptor subunit, but it is the generic parent of the PMF-dependent transporter term asserted by IBA. Reason: True, but entailed by the accepted GO:0009977 proton motive force dependent protein transmembrane transporter activity. |
| GO:0009977 proton motive force dependent protein transmembrane transporter activity | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from the PTN000769484 IBD, seeded by E. coli TatC (P69423). This is the mechanistically specific transporter activity of the Tat translocon. Reason: Core molecular function, well founded at the node by the canonical E. coli TatC. Supporting Evidence: file:PSEAE/tatC/tatC-uniprot.txt transports large folded proteins containing a characteristic twin- |
| GO:0016020 membrane | IEA GO_REF:0000120 | TOO GENERAL | Summary: InterPro/UniProt membrane mapping. True, but GO:0005886 plasma membrane, accepted above, is a descendant. Reason: Entailed by the accepted plasma membrane row. |
| GO:0033281 TAT protein transport complex | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from the PTN000769484 IBD, seeded by E. coli TatC (P69423), this gene (expected self-appearance) and Arabidopsis AT2G01110. TatC is the defining core subunit of the Tat complex. Reason: Core complex membership, well founded at the node. Supporting Evidence: file:PSEAE/tatC/tatC-uniprot.txt The Tat system comprises two distinct complexes: a TatABC |
| GO:0033281 TAT protein transport complex | IEA GO_REF:0000104 | ACCEPT | Summary: UniRule mapping of TAT protein transport complex membership. Reason: Consistent with the accepted IBA/IMP complex rows and the TatC family assignment. |
| GO:0033281 TAT protein transport complex | IMP PMID:16621825 Pyoverdine-mediated iron uptake in Pseudomonas aeruginosa: t... | ACCEPT | Summary: PseudoCAP row and the seed of the PTN000769484 IBD. The cited paper is a tat-pathway phenotype study (PvdN export, pyoverdine), so the IMP evidence for complex membership is indirect, but the membership claim is certainly correct - TatC is the canonical core subunit of the Tat complex by family assignment, and E. coli TatC provides strong experimental grounding at the node. Reason: Sound: the claim is correct and the IBD rests on the well-characterised E. coli TatC, so the seed does not weaken the node even though this paper's evidence is phenotypic. Supporting Evidence: file:PSEAE/tatC/tatC-uniprot.txt Together with TatB, TatC is part of a receptor directly interacting with Tat signal peptides. |
| GO:0043953 protein transport by the Tat complex | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000769484, seeded by E. coli TatC. Protein transport by the Tat complex is the core process TatC enables. Reason: Core process, directly performed as a translocon subunit. Supporting Evidence: file:PSEAE/tatC/tatC-uniprot.txt transports large folded proteins containing a characteristic twin- |
| GO:0043953 protein transport by the Tat complex | IEA GO_REF:0000104 | ACCEPT | Summary: UniRule mapping of the same Tat protein-transport process as the IBA row. Reason: Consistent with the accepted IBA row. |
| GO:0065002 intracellular protein transmembrane transport | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN000769484 for intracellular protein transmembrane transport, seeded by E. coli TatC. A correct, slightly broader description of the Tat translocation TatC carries out. Reason: True and directly performed; sits beside the Tat-specific GO:0043953 term (neither is an is_a ancestor of the other). |
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Experiment: Pull-down or BN-PAGE of tagged PAO1 TatC to define the composition of the TatBC receptor complex and its substrate-dependent association with TatA.
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