I am currently trying to validate my structure using the wwPDB Validation Server before deposition. I am submitting the following files: - Full map - Both half maps - Map-to-structure factors - Coordinate file (.mmCIF) However, when I attempt to submit the entry I receive the following errors: - Coordinate Issues: Not Known - Sequence: The sample sequence has not been provided I have already added the sequence data to the mmCIF file using the Phenix tool: mmtbx.prepare_pdb_deposition After running the tool, I verified that the mmCIF file contains the expected sequence-related records. For example: _entity_poly_seq.entity_id _entity_poly_seq.num _entity_poly_seq.mon_id _entity_poly_seq.hetero 1 1 MET no 1 2 ALA no 1 3 LYS no 1 4 LEU no 1 5 THR no 1 6 LYS no ... (continued) and: loop_ _entity_poly.entity_id _entity_poly.nstd_linkage _entity_poly.nstd_monomer _entity_poly.pdbx_seq_one_letter_code _entity_poly.pdbx_seq_one_letter_code_can _entity_poly.pdbx_strand_id _entity_poly.pdbx_target_identifier _entity_poly.type 1 no no ;MAKLTK ... (continued) For reference the .fasta file looks like this.

Chain A MAKLTK ... (continued)

Despite these sequence records being present in the mmCIF file, the validation server still reports that the sequence has not been provided and flags coordinate-related issues. Has anyone encountered a similar problem or knows what might be causing the validation server to not recognize the sequence information? Any suggestions would be greatly appreciated.