PA0305 (HacB, Q9I6I6) review notes

Review session 2026-11-05 (PseudoCAP IBA-seed protocol, tier 2)

Fetched with just fetch-gene PSEAE Q9I6I6 --alias PA0305; accession matches the worklist.
Unreviewed entry (name from ProtNLM). No deep-research provider was used; literature from the
cached seed paper (abstract only; PubMed MCP gave no full text). Reviewed together with pvdQ and
quiP (shared node PTN002151232; node-level record kept in genes/PSEAE/pvdQ/pvdQ-notes.md).

Literature

PMID:21372094 (Wahjudi et al. 2011), abstract only. Purified PA0305 is processed into alpha
and beta subunits with the catalytic serine at the beta N-terminus, and degrades AHLs
PMID:21372094, with kinetics for C8-HSL and 3-oxo-C12-HSL;
the authors name it HacB.
PMID:16461666 (Huang et al. 2006, full text): a PA0305 transposon mutant grew normally on
C10-HSL, so PA0305 is not the acylase for AHL growth; in that study's E. coli expression the
QuiP activity was reported, not PA0305's.
Location: UniProt periplasm is an ARBA prediction. The sequence begins
MKRTLTVIAVAVAAAAAGGAWYLH, a short basic stretch followed by a hydrophobic segment, consistent
with a Sec signal peptide as in its periplasmic paralogs PvdQ and QuiP (own inspection, not a
SignalP run). Accepted as a family-level location.

Annotation decisions

GO:0016811 (IBA, IDA, IEA): ACCEPT, core MF.
GO:0016787 (IEA): TOO_GENERAL.
GO:0017000 antibiotic biosynthetic process (IEA): REMOVE.
GO:0042597 periplasmic space (IEA): ACCEPT.
Action counts: ACCEPT 4, TOO_GENERAL 1, REMOVE 1.

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?
PTN002151232	GO:0016811 hydrolase activity, acting on carbon-nitrogen (but not peptide) bonds, in linear amides	3	21 (13 taxa)	GO:0016811, IDA, PMID:21372094 (PseudoCAP)	SOUND	Abstract reports purified enzyme degrading C6-C14 AHLs with kcat/Km values.	pvdQ Q9I194 (IDA), quiP Q9I4U2 (IMP; heterologous activity)	Yes (see pvdQ notes for the node-level record)

No PSEUDOCAP or GO_CENTRAL defect on PA0305.