TatA (PA5068) is the small single-pass inner-membrane subunit of the twin-arginine translocation (Tat) system of Pseudomonas aeruginosa, encoded upstream of tatB and tatC. The Tat system moves folded proteins with twin-arginine signal peptides across the cytoplasmic membrane, driven by the proton motive force. Substrates bind a TatBC receptor complex, which recruits oligomeric TatA; TatA is thought to form the protein-conducting channel. In P. aeruginosa the Tat pathway exports the periplasmic pyoverdine-biogenesis protein PvdN, so tat mutants make no pyoverdine, as well as phospholipases and other secreted virulence-associated proteins.
| GO Term | Evidence | Action | Reason |
|---|---|---|---|
| GO:0005886 plasma membrane | IEA GO_REF:0000120 | ACCEPT | Summary: HAMAP-based cell inner membrane mapping; one N-terminal TM helix. Reason: TatA acts in the cytoplasmic (inner) membrane, which is the bacterial plasma membrane. Supporting Evidence: file:PSEAE/tatA/tatA-uniprot.txt Cell inner membrane |
| GO:0008320 transmembrane protein transporter activity | IBA GO_REF:0000033 | MODIFY | Summary: IBA from the three-seed PTN002452729 IBD (E. coli TatA, TatE and this gene). Reason: Correct but general. Tat transport is driven by the proton motive force, and GO:0009977 (is_a GO:0008320) is the supported specific term, also used for TatC. Propagation Review Root cause: TERM SCOPING PROBLEM Failure modes: GRANULARITY MISMATCH Sources checked: PANTHER:PTN002452729 · PTN002452729 SUPPORTS TRANSFER TatA/E clade node seeded by E. coli TatA and TatE (IGI) and by this gene; the inherited claim is right, and the more specific PMF-dependent term is supported by E. coli TatA IDA. UniProtKB:Q9HUB5 · tatA (self; PseudoCAP IMP PMID:16621825) SUPPORTS TRANSFER Expected self-seed; claim correct, evidence a tat-mutant export phenotype. Proposed replacements: proton motive force dependent protein transmembrane transporter activity Supporting Evidence: file:PSEAE/tatA/tatA-uniprot.txt TatA could form the protein-conducting channel of the Tat system. file:PSEAE/tatA/tatA-uniprot.txt Substrates initially bind to the TatABC complex, which probably triggers association of the separate TatA complex to form the active translocon. |
| GO:0008320 transmembrane protein transporter activity | IEA GO_REF:0000120 | MODIFY | Summary: Combined electronic mapping (HAMAP TatA/E). Reason: Same claim and refinement as the IBA row. Proposed replacements: proton motive force dependent protein transmembrane transporter activity Supporting Evidence: file:PSEAE/tatA/tatA-uniprot.txt TatA could form the protein-conducting channel of the Tat system. |
| GO:0008320 transmembrane protein transporter activity | IMP PMID:16621825 Pyoverdine-mediated iron uptake in Pseudomonas aeruginosa: t... | MODIFY | Summary: PseudoCAP row and a seed of PTN002452729. The paper shows Tat-dependent export of PvdN in a tat mutant; it does not name the mutated gene in the abstract. Reason: Seed verdict SOUND: the activity is right for TatA, though the evidence is an export phenotype. Refine to GO:0009977, as for the other GO:0008320 rows. The IBD also stands on E. coli TatA and TatE. Proposed replacements: proton motive force dependent protein transmembrane transporter activity Supporting Evidence: PMID:16621825 We located PvdN, a still unknown but essential component in Pvd biogenesis, at the periplasmic side of the cytoplasmic membrane and showed that its export is Tat dependent. file:PSEAE/tatA/tatA-uniprot.txt TatA could form the protein-conducting channel of the Tat system. |
| GO:0015031 protein transport | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO mapping. Reason: True, but GO:0043953 protein transport by the Tat complex, accepted here, is_a GO:0015031. |
| GO:0016020 membrane | IEA GO_REF:0000002 | TOO GENERAL | Summary: InterPro2GO mapping. Reason: True, but GO:0005886 plasma membrane, accepted here, is_a membrane. |
| GO:0033281 TAT protein transport complex | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN002452729, seeded by E. coli TatA (IDA), TatE and this gene. Reason: TatA is a core subunit of the Tat translocase; the node term suits the TatA/E clade. Supporting Evidence: file:PSEAE/tatA/tatA-uniprot.txt Substrates initially bind to the TatABC complex, which probably triggers association of the separate TatA complex to form the active translocon. |
| GO:0033281 TAT protein transport complex | IEA GO_REF:0000120 | ACCEPT | Summary: Combined electronic mapping (HAMAP TatA/E). Reason: Same claim as the IBA row. Supporting Evidence: file:PSEAE/tatA/tatA-uniprot.txt Substrates initially bind to the TatABC complex, which probably triggers association of the separate TatA complex to form the active translocon. |
| GO:0033281 TAT protein transport complex | IMP PMID:16621825 Pyoverdine-mediated iron uptake in Pseudomonas aeruginosa: t... | ACCEPT | Summary: PseudoCAP row and a seed of PTN002452729. The evidence is a tat-mutant export phenotype, which supports complex membership only indirectly. Reason: Seed verdict SOUND, as for the same paper's row on tatC: the membership claim is certainly correct by family assignment (HAMAP MF_00236), and the IBD rests also on E. coli TatA, which has direct evidence. Supporting Evidence: file:PSEAE/tatA/tatA-uniprot.txt Substrates initially bind to the TatABC complex, which probably triggers association of the separate TatA complex to form the active translocon. PMID:16621825 We located PvdN, a still unknown but essential component in Pvd biogenesis, at the periplasmic side of the cytoplasmic membrane and showed that its export is Tat dependent. |
| GO:0043953 protein transport by the Tat complex | IBA GO_REF:0000033 | ACCEPT | Summary: IBA from PTN002452729, seeded by E. coli TatA and TatE; tatA is not a seed of this term. Reason: Core process; in P. aeruginosa the Tat pathway exports PvdN. Supporting Evidence: PMID:16621825 We located PvdN, a still unknown but essential component in Pvd biogenesis, at the periplasmic side of the cytoplasmic membrane and showed that its export is Tat dependent. file:PSEAE/tatA/tatA-uniprot.txt TatA could form the protein-conducting channel of the Tat system. |
| GO:0043953 protein transport by the Tat complex | IEA GO_REF:0000120 | ACCEPT | Summary: Combined electronic mapping. Reason: Same claim as the IBA row. Supporting Evidence: file:PSEAE/tatA/tatA-uniprot.txt TatA could form the protein-conducting channel of the Tat system. |
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