Protein Data Bank (PDB) Archive: a new architecture (beta) for scalable, PDBx/mmCIF-based data distribution.

With the continuous growth of the Protein Data Bank archive, the Worldwide Protein Data Bank (wwPDB) partnership anticipates that the entire complement of possible four-character PDB accession codes (for example 1ABC) will be exhausted by 2028. wwPDB is, therefore, revising the PDB accession code (PDB ID) to 12 characters by extending its length and prepending `pdb_' (for example pdb_1000axyz) in lower case. This change will enable the robust detection of references to PDB entries in published literature. On or about July 21st 2027, the PDB will convert to releasing entries with extended PDB IDs only, which will not be compatible with the legacy PDB format. A beta version of the PDB Archive (PDB Beta Archive) is now available to help communities adapt to and embrace the extended PDB IDs and PDBx/mmCIF format during a transition phase. All files in the current PDB archive are reorganized in the Beta Archive with extended PDB IDs (including file naming and directories) on an entry-level basis, mirroring the data organization of the PDB Versioned Archive. wwPDB encourages scientific journals, PDB community members and users to transition to the PDBx/mmCIF format and adopt the new PDB ID format as early as possible. The PDB Beta Archive will replace the current public archive, and 12-character PDB IDs will be solely assigned to all newly deposited PDB entries.