oprB (PA3186, Q51485) notes

Review session 2026-10-28 (PseudoCAP IBA-seed protocol)

Fetched with just fetch-gene PSEAE oprB. Accession Q51485 matches the worklist
(rank 81). Swiss-Prot reviewed entry PORB_PSEAE (PE 1). No deep-research
provider was used.

Identity and literature

OprB (outer membrane protein D1, glucose porin) is the glucose-inducible,
carbohydrate-selective outer-membrane porin; Pfam PF04966 OprB, InterPro
IPR007049 Carb-sel_porin_OprB, TCDB 1.B.19.1.1, PANTHER PTHR37944 "PORIN B".
Signal peptide 1-31 confirmed by N-terminal sequencing (UniProt, PMID:8132494).
Wylie and Worobec 1995 (PMID:7768797; abstract only in the cache; full text
supplied by the user and read 2026-11-05: whole-cell radiolabelled uptake in
oprB interposon mutant, complemented and overexpressing strains, no assay on
purified OprB, so the PseudoCAP IDA should be IMP; defect CONFIRMED):
PMID:7768797
PMID:7768797
PMID:7768797
UniProt curated function [file:PSEAE/oprB/oprB-uniprot.txt "Involved in the
transport of glucose, mannitol, fructose and glycerol (sugars able to support
the growth of P.aeruginosa). Facilitates glucose diffusion across the outer
membrane."]. UniProt also cites liposome channel specificity work (Trias et al.
1988, PMID:2450582) and biophysical characterisation (PMID:8132494), neither
cached.

Evidence type (from the abstract only; no PMC body text, 2026-10-29):
whole-cell initial uptake in mutant and overexpression strains. That reads as
IMP rather than IDA, but the full text could hold a direct assay, so the
defect is SUSPECTED, not PROBABLE (2026-10-29 audit). The claim (OprB conducts sugars across the outer
membrane) is sound and OprB does the transport work as the channel.

Clade check for PTN002209977 (cached PAINT leaf GAF; QuickGO 2026-10-28)

10 leaves in 5 taxa: OprB (Q51485) and PAO1 paralogs PA2291 ("probable
glucose-sensitive porin") and PA4099; Bradyrhizobium bll2003, blr2272, blr3947,
blr8037; Synechocystis slr1163; Xanthomonas campestris RpfN; Rhodopirellula
RB9508 ("carbohydrate-selective porin OprB"). QuickGO shows no experimental
annotations for any leaf other than OprB. All belong to the OprB
carbohydrate-selective porin family, so a carbohydrate transport node term is
a reasonable family-level claim.

PseudoCAP IBA-seed assessment

PTN node	node term	n_seeds	leaf IBAs	seed annotation (term, evidence, PMID)	verdict	rationale
PTN002209977	GO:0008643 carbohydrate transport	1 (sole)	10 (5 taxa)	GO:0008643, IDA, PMID:7768797 (PseudoCAP)	SOUND	Uptake of glucose, mannitol, fructose and glycerol (not arginine) tracks OprB loss and overexpression; OprB is the channel. Evidence should be IMP (full text checked). The node term is a general family-level property of OprB-family carbohydrate-selective porins and suits this small clade.

Defects filed: PSEUDOCAP WRONG_EVIDENCE_CODE (IDA -> IMP, CHECK) on the
experimental row. No GO_CENTRAL defect.

Decisions summary

ACCEPT: cell outer membrane (IEA), porin activity (IEA).
MODIFY: carbohydrate transport (IBA, IDA, IEA) and transmembrane transport
(IEA) -> D-glucose, mannitol, fructose and glycerol transmembrane transport;
membrane -> cell outer membrane.