Phase 5n-lite — N-glycosylation map + calnexin retention proxy on STRC
Tests the ‘extended calnexin retention’ rate-limiting step candidate from STRC E1659A QC Rate-Limiting Step Lit Gap-Map. Sequon = NX[ST], X ≠ P. Coordinates from Phase 5d snap_010 (full-length E1659A MD-relaxed).
Summary
- STRC length: 1775 aa
- WT N-glyc sequons: 14
- E1659A vs WT: +0 created (—), −0 destroyed (—)
- Nearest sequon to E1659: N1179 (NLT), 29.8 Å
- Nearest sequon to K1141: N1179 (NLT), 29.7 Å
- Sequons within 25 Å of E1659: 0 | within 50 Å: 3
- Sequons within 25 Å of K1141: 0 | within 50 Å: 3
Domain distribution
| Domain | Range | N-glyc sequons |
|---|---|---|
| N-terminal | 1-799 | 9 |
| Central FN3-like | 800-1200 | 4 |
| Linker | 1201-1500 | 1 |
| C-terminal ZP-like | 1501-1771 | 0 |
Interpretation
- E1659A in a moderate N-glyc neighbourhood (3 sequons within 50 Å, only 0 within 25 Å). Calnexin retention plausible but not dominant.
- E1659A does not perturb N-glyc landscape directly (0 sequons created/destroyed). Effect on QC must be via fold-stability + calnexin re-glucosylation, not via primary glyc-sequon disruption.