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Usage Note

As structures containing multiple character chain ids, >62 chains and/or 99999 ATOM lines cannot be represented in the legacy PDB file format, data are available in the PDB archive as:

Historically, large files containing >62 chains and/or 99999 ATOM lines were "split" across multiple PDB format files. These files were combined into single entries at the end of 2014 (wwPDB Announcement). An index file mapping large structures to corresponding obsoleted split entries is available at This file does not list large structures that were never deposited as split entries.