sltB1 (PA4001, Q9HX24) notes

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

Fetched with just fetch-gene PSEAE Q9HX24 --alias sltB1; accession matches the worklist. No
deep-research provider was used.

Literature

Blackburn & Clarke 2002 (PMID:11790124, abstract only): two P. aeruginosa family 3 LTs found by
homology to E. coli MltB; the palmitoylated one was named MltB, the non-lipidated one SltB.
PMID:11790124;
SltB more efficient (kcat/KM) than sMltB. PA4001 has a SignalP signal peptide and no lipobox, so it is
the soluble enzyme (SltB, later SltB1).
Legaree & Clarke 2008 (PMID:18708507, full text): PMID:18708507;
SltB1 binds PBP2 (affinity chromatography, SPR), through the N-terminal non-PB module of PBP2; sltB1 is
clustered with PG-synthesis genes.
Structure PDB 4ANR shows a Ca2+-binding EF-hand-like loop (UniProt FT BINDING 210-225).

Annotation decisions

GO:0008933 IBA and IDA: ACCEPT. GO:0009253 IBA: ACCEPT.
GO:0005515 IPI (PBP2): REMOVE (protein-binding policy).
Action counts: ACCEPT 3, REMOVE 1. 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:11790124 (PseudoCAP)	SOUND	Abstract states the purified soluble enzyme releases anhydromuropeptides from insoluble PG (decisive fact stated outright). Node term suits the GH103 MltB-like clade.	E. coli MltB P41052; P. aeruginosa MltB1 Q9HVX3 and SltB3 Q9HX28 (both also SOUND)	Yes

The node's GO:0009253 IBD is seeded by E. coli MltB (P41052) alone and is not a PseudoCAP seed. Shared
node with mltB1 and PA3992: all three seeds SOUND, no node-level GO_CENTRAL defect.