ccpA (PA4587, P14532) notes

Di-heme cytochrome c551 peroxidase (CCP, EC 1.11.1.5), periplasmic. No deep-research provider
was available; literature search by hand (PubMed metadata for PMID:1657179; cached abstract for
PMID:8591033 fetched with ai-gene-review fetch-pmid; QuickGO for the E. coli Ccp seed P37197).

Literature

Fülöp et al. 1995 (PMID:8591033; abstract): crystal structure; two class-I cytochrome c-like
domains each with a covalent heme c; low-potential heme (-330 mV) is the peroxidatic site, the
high-potential heme (+320 mV) takes electrons from cytochrome c and azurin ["one of them is a
low-potential (-330 mV) centre where hydrogen peroxide is reduced (the peroxidatic site)"];
periplasmic, likely peroxide protection ["The enzyme is located in the bacterial periplasm where
its likely function is to provide protection against toxic peroxides."].
Ellfolk et al. 1991 (PMID:1657179; abstract only): structure-function study of purified
Pseudomonas CCP, native enzyme versus elastase two-fragment complex; Lys replaces Met at heme 1
"thus making peroxidatic activity possible". UniProt cites this paper for EC 1.11.1.5.
E. coli Ccp (P37197): EcoCyc IDA GO:0004130 and GO:0019645 (PMID:28696311); a quinol
peroxidase used for H2O2 respiration under anaerobiosis, a different electron donor and
membrane association from CcpA.

Review decisions

GO:0004130 (IBA, IDA, IEA): ACCEPT, core.
GO:0016491: TOO_GENERAL (entailed by GO:0004130). GO:0009055: MARK_AS_OVER_ANNOTATED
(internal electron relay is part of the peroxidase reaction). GO:0020037: KEEP_AS_NON_CORE.
GO:0019645 IBA (PTN002023662, E. coli Ccp sole seed): MARK_AS_OVER_ANNOTATED; respiratory role
not shown for CcpA. GO:0042743 IBA: MODIFY to GO:0042744 hydrogen peroxide catabolic process.
GO:0042597, GO:0098869: ACCEPT.

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?
PTN000779264	GO:0004130 cytochrome-c peroxidase activity	2	44 (17 taxa)	GO:0004130, IDA, PMID:1657179 (PseudoCAP)	SOUND	The term is correct for CcpA (type member of the di-heme CCP family; structure and UniProt-curated EC). Abstract-only: the paper studies the purified enzyme's structure-function; whether activity was assayed in this paper is not visible, but nothing suggests a wrong term. Node term suits a di-heme CCP clade.	E. coli Ccp P37197 (EcoCyc IDA GO:0004130, PMID:28696311)	Yes, on E. coli Ccp

No PSEUDOCAP or GO_CENTRAL defect.