mucA (PA0763, P38107) notes

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

Fetched with just fetch-gene PSEAE P38107 --alias mucA; accession matches the worklist.
Reviewed (Swiss-Prot) entry. No deep-research provider was used. Literature from the cached
papers; PubMed and Europe PMC searches failed (NCBI eutils HTTP 500, Europe PMC 503) during
this session. Read with the algU, mucB and fpvR/PA0471/foxR reviews for consistency.

Literature

PMID:8759866 (Schurr et al. 1996), abstract only in cache: PMID:8759866
PMID:19226327 (Wood and Ohman 2009), abstract: PMID:19226327; cell wall stress triggers AlgW then YaeL cleavage (RIP).
PMID:19298369 (Cezairliyan and Sauer 2009), full text: PMID:19298369; MucB binding
blocks AlgW cleavage.
PMID:22842599 (Pulcrano et al. 2012), abstract only: mucA mutations in CF isolates and algU
expression.
UniProt P38107: RseA family, RseA_N (PF03872) and RseA_C (PF03873), TM helix 89-105;
structures 6IN7/8Z6G (residues 1-80) and 6IN9/6JAU (106-194).

Annotation decisions

GO:0016989 sigma factor antagonist activity: IBA, IEA, IMP all ACCEPT (core).
GO:0045892 (IEA): MODIFY to GO:2000143 (as on fpvR, PA0471, foxR).
GO:0032885 regulation of polysaccharide biosynthetic process (IMP): KEEP_AS_NON_CORE; GO has
no negative-regulation child.
GO:0005886 plasma membrane (IEA): ACCEPT.
GO:0005515 protein binding x3 (MucB x2, AlgW): REMOVE per the protein-binding policy.
Action counts: ACCEPT 4, MODIFY 1, KEEP_AS_NON_CORE 1, REMOVE 3.

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?
PTN002211401	GO:0016989 sigma factor antagonist activity	2	8 (8 taxa)	GO:0016989, IMP, PMID:22842599	SOUND	Truncating mucA mutations in CF isolates derepress algU (autoregulated) and alginate genes: the standard derepression evidence for an anti-sigma factor; direct binding and inhibition in PMID:8759866.	E. coli RseA (P0AFX7; EcoCyc IMP PMID:9159522, ComplexPortal IPI)	Yes

MucA is not on PTN001250434 (the FecR-family node of fpvR, PA0471, foxR); its node is the
RseA family. Leaves (.cache/paint/leaf.gaf.gz): RseA of E. coli, Salmonella, Yersinia,
Haemophilus, Shewanella, Vibrio and Xanthomonas XCC1268, plus MucA. All are RseA-family
anti-sigma-E factors, so the node term suits the clade. No PSEUDOCAP or GO_CENTRAL defects.