## ERO1B
- **UniProt:** Q86YB8 · **batch:** proteostasis-batch-2026-06-07b · **review status:** COMPLETE
- **PN placement:** `ER proteostasis|Folding enzyme|Protein disulfide isomerases|Protein disulfide isomerase reoxidation`. **PN-node mapping:** type `PDI reoxidation`=mapped→**GO:0016971 flavin-dependent sulfhydryl oxidase activity** (corrected in batch-5); parent group `Protein disulfide isomerases`=mapped→**GO:0003756 protein disulfide isomerase activity** (new_to_goa); class/branch=no_mapping. (Identical node/mapping structure to ERO1A.)
- **Consistency:** Notes, review YAML, and the corrected PN type mapping agree: ERO1B is an FAD-dependent sulfhydryl OXIDASE (paralog of ERO1A, more active/loosely regulated, secretory-tissue enriched) that reoxidizes PDI. Review core MF = GO:0016971 (EXP PMID:11707400/21091435, ACCEPT) and it **MARK_AS_OVER_ANNOTATED** the GO:0015035 protein-disulfide reductase rows (IEA + three Reactome EXP rows) for wrong directionality. **Same internal PN tension as ERO1A:** the parent group still maps GO:0003756 and the projected list still projects GO:0003756 to ERO1B as new_to_goa, contradicting the corrected type node and the review.
- **PN story / NEW pressure:** GO:0016971 (OLS-verified) is in GOA (EXP) and ACCEPTed — captured. GO:0003756 (verified real) should NOT be added: ERO1B is an oxidase, not an isomerase (the review never asserts isomerase activity and rejects the reductase mislabel). Conclusion on the group projection: **over-reaches** for ERO1B. One nuance the review surfaces that PN does not: a genuine tissue-specific role in oxidative proinsulin folding (GO:0030070 insulin processing, KEEP_AS_NON_CORE) — enrichment, not conflict.
- **Mapping strategy:** Type-level correction (→GO:0016971) is right; the residual group-level GO:0003756 inheritance is the only problem, arising because `Protein disulfide isomerases` mixes catalytic isomerases, non-catalytic members and oxidases. ERO1B is the cleanest illustration: it carries three EXP reductase rows that the review actively rejects on directionality grounds, so propagating the isomerase term to it is doubly inappropriate.
- **Evidence alignment:** PN dossier lists no reference titles. Review oxidase evidence (PMID:11707400, 21091435, 10818100; plus the rejected reductase sources PMID:16407158, 21091435 Reactome) is reviewer-supplied. ERO1B↔P4HB relay biology mirrors the P4HB review. Alignment by shared biology, not citation list.
- **Verdict:** Consistent at the (corrected) gene/type level; GO:0016971 validated and captured. The **group-level GO:0003756 projection over-reaches** and should not land on ERO1B (same fix as ERO1A). **Recommended edits:** [MAP] suppress/override the GO:0003756 projection for ERO1B so PDI-reoxidation oxidase children inherit only GO:0016971 (consistent with the corrected type node and the review's explicit oxidase-not-isomerase / not-reductase stance).