Validation statistics for models from Data S2. (a–e) OFS-C3 (a); OFS_out, D390 down (b); OFS_out, D390 up (c); OFS_mid (d); OFS_in (e). From left to right, map FSC from NU-refinement in cryoSPARC, model-to-data validation in Phenix of the trimer, and local resolution estimation. All maps are contoured at 8 σ except a, which is contoured at 10 σ. The top protomer in b–e is the subject of focused classification and model refinement.