PA5455 (PA5455, Q9HTB5) review notes

No deep-research API was available. Manual research on 2026-11-05: full text of
PMID:23341552 (cached, PMC3560663), a Europe PMC search for "(PA5455 OR PA5456)
AND glycosyltransferase" and for common polysaccharide antigen titles (PubMed MCP
and NCBI E-utilities returned server errors), and the UniProt record (unreviewed,
PE 4).

Biology

PA5455 (542 aa) is a predicted GT-B fold, GT4-family glycosyltransferase (Pfam
PF13692 Glyco_trans_1_4; SUPFAM SSF53756; PANTHER PTHR46656:SF3) in the
pa5455-pa5459 operon beside the rmd-wbpZ CPA cluster PMID:23341552.
Deletion of PA5455 (in-frame, nonpolar) abolishes CPA; complementation restores it
PMID:23341552.
Co-overexpression of PA5455 and PA5456 shortens CPA chains; the authors suggest a
chain-length-determining or chain-terminating role PMID:23341552. They speculate PA5455 and
PA5456 may act as a complex, without data.
The paper's own summary of its evidence PMID:23341552. Methods are RT-PCR, 5'-RACE,
EMSA with E. coli RNA polymerase, promoter-trap beta-galactosidase assays,
deletion mutants and arabinose-induced overexpression. No glycosyltransferase
assay, no purified PA5455/PA5456.
The D-rhamnan backbone of CPA is made by WbpZ, WbpY and WbpX, which have been
assayed in vitro (PMID:25845842; PMID:35166992, not cached); no later paper
found assays PA5455 or PA5456.

PseudoCAP IBA-seed assessment

PTN node	node term	n_seeds	leaf IBAs	seed annotation (term, evidence, PMID)	verdict	rationale	other seeds	IBD stands without this seed?
PTN002288302	GO:0016757 glycosyltransferase activity	2	57 (43 taxa)	GO:0016757, IDA, PMID:23341552 (PseudoCAP)	UNVERIFIABLE	Full text read: GT activity is a sequence prediction; only genetics reported. The IDA code is wrong; the claim is plausible from the GT4 domain.	PA5456 (same paper, same problem)	No: the only other seed has the same defect, so the IBD has no experimental seed. Term likely true by domain.

Defects: PSEUDOCAP WRONG_EVIDENCE_CODE (CONFIRMED) on the GO:0016757 IDA row and
on the GO:0009243 IDA row (should be IMP). The node-level GO_CENTRAL defect (OTHER, CHECK, CONFIRMED) is recorded once, on the PA5455 IBA row; PA5456 shares the node and the same verdict.

Action summary

ACCEPT: GO:0016757 (IBA, IDA), GO:0009243 (IDA). TOO_GENERAL: GO:0009103 (IMP).