fimT (PA4549, UniProt Q9HVN0) review notes

No deep-research provider was available. These notes come from my own reading
of the cached publications, PubMed/Europe PMC searches, live QuickGO queries
(2026-11-03) and the UniProt entry.

Identity

• just fetch-gene PSEAE fimT resolved to Q9HVN0 (Q9HVN0_PSEAE), PA4549,
  169 aa, unreviewed (TrEMBL), PE 3. The accession matches the one named in
  the task.
• UniProt recommended name "Type II secretion system protein H" and the
  inner-membrane location are ARBA predictions (ECO:0000256|ARBA), not
  curated statements.
• Family: InterPro IPR022346 T2SS_GspH, Pfam PF12019 GspH (domain 47-148),
  Pfam PF07963 N_methyl, NCBIfam TIGR02532 IV_pilin_GFxxxE, SUPFAM "Pili
  subunits" [file:PSEAE/fimT/fimT-uniprot.txt]. No PANTHER xref in the
  entry, so no PAINT node reaches it (QuickGO lists no IBA rows).
• No nuclease domain or catalytic motif of any kind; this is a small
  class III prepilin-like protein.
• P. aeruginosa has a separate T2SS GspH, XcpU (PA3100, Q00515; UniProt REST
  query), and the neighbouring paralogue FimU (PA4550, G3XCZ0).

Literature

• Discovery: fimT and fimU lie between pilR and pilV and encode prepilin-like
  proteins. fimT mutants are wild type; FimT overexpression replaces FimU
  [PMID:8682785 "whereas the fimT and dada* mutants retained wild-type
  phenotypes"; "overexpression of the fimT gene was found to be able to
  functionally replace the lack of a fimU gene product, suggesting a subtle
  role in fimbrial biogenesis"]. Full text (PMC232641) could not be
  retrieved by the PubMed MCP; abstract only.
• The P. aeruginosa minor pilin papers from the Burrows lab study FimU,
  PilV, PilW, PilX and PilE; FimT is not among the minor pilins they assay
  PMID:20338182.
  The full-text caches of PMID:25389296, PMID:26359492 and PMID:29775484
  contain no mention of FimT (text search).
• FimT/FimU family includes the T2SS GspH PMID:35246533.
• DNA binding: purified P. aeruginosa FimT binds a 30 bp dsDNA in EMSA,
  whereas P. aeruginosa FimU does not [PMID:35246533 "We expressed and
  purified FimT and FimU from the human pathogen P. aeruginosa and the plant
  pathogen Xanthomonas campestris (both γ-Proteobacteria) and performed
  EMSAs to assess DNA binding in vitro"; "Interestingly, FimT from both
  species binds to DNA and the affinity appears to be within the same order
  of magnitude as L. pneumophila FimT."; "On the other hand, FimU does not
  interact with DNA"]. Full-length FimTPa did not restore transformation
  in a Legionella fimT mutant, but its C-terminal D-region grafted onto
  Legionella FimT did PMID:35246533. The binding is
  non-sequence-specific and electrostatic in the Legionella protein. PAO1 is
  not known to be naturally transformable, so the physiological role of FimT
  DNA binding in P. aeruginosa is unknown.

The GO:0016888 row (PseudoCAP IDA, PMID:18174131)

Live QuickGO, 2026-11-03:

• geneProductId=Q9HVN0: 5 rows. GO:0016888 enables, IDA, PMID:18174131,
  PseudoCAP, 20190311 (no WITH/FROM). Also GO:0043683 IDA PMID:8682785
  PseudoCAP 20190311, and three InterPro/UniProt IEAs.
• reference=PMID:18174131&assignedBy=PseudoCAP: 4 rows, all 20190311:
  P22608 pilB GO:0016887; P24559 pilT GO:0016887; G3XCX3 pilU GO:0016888;
  Q9HVN0 fimT GO:0016888.

PMID:18174131 is Chiang et al. 2008, ATPase assays and NTPase-motif
mutagenesis of PilB, PilT and PilU PMID:18174131. Abstract only: no PMC copy
(PMID-to-PMCID conversion returns none), the publisher page returned 403, and
Europe PMC text-mined gene mentions are only ATPase/NTPase terms. I have not
read the full text.

Assessment:

1. GO:0016888 is wrong for FimT. CONFIRMED from primary data: the live
   QuickGO query shows the identical wrong id on the pilU row from the same
   paper and date, while pilB and pilT got the adjacent GO:0016887; the
   completed pilU review established that slip. FimT's sequence has no
   nuclease domain (GspH/N_methyl pilin only), and no paper reports nuclease
   activity for any FimT.
2. The paper probably has nothing on FimT, so repointing to GO:0016887 is
   not the fix. The abstract positively names PilB, PilT and PilU as the
   proteins purified and mutated and calls them motor proteins; FimT is a
   minor pilin, not an NTPase, so it cannot be one of the ATPases. The fimT
   row looks like a duplicate of the pilU row keyed onto the wrong gene
   product (the pilU row already exists, so the fimT copy should be deleted,
   not moved). Confidence PROBABLE: I read only the abstract, so I cannot
   exclude that the full text uses FimT somehow (e.g. as a control), but no
   reading of an NTPase paper would support a nuclease or ATPase function
   for a pilin.
3. Cause of the gene-product slip: unknown. PA4549 and PA0396 are not
   similar locus tags; pilB is PA4526, near PA4549 in the genome, but pilB's
   row from the paper is separate and correct.

Recorded as two PSEUDOCAP source defects on the row: WRONG_TERM (CONFIRMED,
requested_change CHECK, since the corrected term depends on point 2) and
WRONG_GENE_PRODUCT (PROBABLE, DELETE_ROW, the pilU row G3XCX3 being where the
assertion belongs).

PseudoCAP IBA-seed assessment

fimT (PA4549, Q9HVN0) is not in projects/PSEUDOCAP/iba_seed_worklist.yaml:
none of its PseudoCAP rows seeds a PAINT IBD with PseudoCAP support. It also
receives no IBA (no PANTHER family assignment in UniProt; QuickGO returns no
GO_REF:0000033 rows), so there is no IBA to assess.

Decisions summary

• ACCEPT: plasma membrane (IEA); type IV pilus assembly (IDA).
• REMOVE: type II protein secretion system complex and protein secretion by
  the type II secretion system (IEA, IPR022346): domain shared with
  T2SS GspH; XcpU is the Xcp GspH. Consistent with the fimU review.
• REMOVE: DNA endonuclease activity (IDA, PMID:18174131), with two PseudoCAP
  source defects.
• NEW: double-stranded DNA binding (GO:0003690), IDA, PMID:35246533 (EMSA of
  purified P. aeruginosa FimT with 30 bp dsDNA).