## DDA1
- **UniProt:** Q9BW61 · **batch:** proteostasis-batch-2026-06-13 · **review status:** COMPLETE
- **PN placement:** `UPS|E3 ubiquitin and UBL ligases|Cul4A/Cul4B receptor scaffold` ; **PN-node mapping:** group "Cul4A/Cul4B receptor scaffold"=mapped, ok_for_propagation, **GO:0160072** (ubiquitin ligase complex scaffold activity); projected goa_status=new_to_goa.
- **Consistency:** Consistent on biology — deep research, review and PN all describe DDA1 as a small shared CRL4 subunit that stabilizes the DDB1-DCAF assembly (not a receptor, not catalytic). Slight MF-vocabulary divergence: review assigns molecular_function GO:0005198 (structural molecule activity) with contributes_to GO:0061630, whereas PN maps the node to GO:0160072 (scaffold activity). No biological contradiction; both capture a non-catalytic structural/scaffolding role.
- **PN story / NEW pressure:** PN projects GO:0160072 (scaffold) as new_to_goa — confirmed absent from DDA1 GOA (goa.tsv has no MF scaffold/adaptor term). GO:0160072 is real (OLS: brings together a ubiquitin ligase and a ligase-substrate adaptor). DDA1 stabilizes/positions the DCAF receptor and the ligase, so a scaffold-class MF is defensible, though GO:0160072's exact definition (bridging ligase + adaptor) is a tighter fit for DDB1 than for the small accessory DDA1. Verdict: defensible ADD, but borderline — DDA1 is better described as a stabilizing/structural subunit than as the bridging scaffold itself.
- **Mapping strategy:** Node correctly distinguishes DDA1 ("receptor scaffold") from the substrate receptors (GO:1990756) and from catalysis — a good distinction. Status/scope appropriate. The review's GO:0005198 is arguably the more conservative MF; GO:0160072 leans into the scaffold framing.
- **Evidence alignment:** PN ref 17452440 = Pick et al. 2007 (DDD/DET1-DDA1-DDB1, UBE2E recruitment); the review cites this framework via PMID:16949367 and the falcon synthesis (Shabek 2018 structure, Schiffmacher 2024 CRL4(CSA)/TC-NER). Strong structural evidence (PMID:30564455, 31686031) underpins the stabilizing role. No conflict.
- **Verdict:** Consistent; GO:0160072 (scaffold) is a defensible-but-borderline add vs the review's GO:0005198. **Recommended edits:** [YAML] optionally add GO:0160072 to DDA1 core MF (or reconcile GO:0005198 vs GO:0160072) to align the review with the PN scaffold projection.