PA3992 (SltB3, Q9HX28) notes

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

Fetched with just fetch-gene PSEAE Q9HX28 --alias PA3992; accession matches the worklist. No gene
name in UniProt; folder and symbol use the locus tag. PMID:27035839 cached with just fetch-pmid
(full text, PMC5436585). No deep-research provider was used.

Literature

Lee et al. 2016 (PMID:27035839, full text): PMID:27035839
SltB3 is exolytic: PMID:27035839
Kinetics on a synthetic tetrasaccharide-pentapeptide substrate: PMID:27035839
It also processes a 20-sugar peptidoglycan strand; X-ray structures (5ANZ, 5AO7, 5AO8) show four
domains in an annulus through which the glycan strand threads.
UniProt predicts a lipobox (PRU00303, Cys31), but the paper calls SltB3 a soluble LT and
Legaree & Clarke 2008 (PMID:18708507) list SltB3 among the soluble paralogs; no CC annotation is under
review, so this is noted only.

Annotation decisions

GO:0008933 IBA and IDA: ACCEPT. GO:0009253 IBA: ACCEPT. GO:0009254 peptidoglycan turnover IDA: ACCEPT
(the enzyme performs the breakdown step of turnover; the paper frames it as turnover in recycling).
Action counts: ACCEPT 4. No source defects.

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?
PTN002410022	GO:0008933 peptidoglycan lytic transglycosylase activity	4	34 (18 taxa)	GO:0008933, IDA, PMID:27035839 (PseudoCAP)	SOUND	Full text read: purified SltB3 turns over PG substrates to GlcNAc-1,6-anhydroMurNAc with measured kinetics. GO:0008933 explicitly includes exolytic activity. Node term suits the GH103 clade.	E. coli MltB P41052; P. aeruginosa SltB1 Q9HX24 and MltB1 Q9HVX3 (both SOUND)	Yes

Shared node with sltB1 and mltB1 (see genes/PSEAE/sltB1/sltB1-notes.md): all seeds SOUND, no
GO_CENTRAL defect.