    New chain ID            Original chain ID

12dl-pdb-bundle1.pdb:
           A                        FA
           B                        GB
           C                        GA
           D                        IA
           E                        HB
           F                        HA
           G                        KA
           H                        LA
           I                        MA
           J                        AC
           K                        AD
           L                        AE
           M                        AF
           N                        AG
           O                        AH
           P                        AA
           Q                        AB
           R                        AI
           S                        AJ
           T                        EA
           U                        DA

12dl-pdb-bundle2.pdb:
           A                        DB
           B                        BA
           C                        BB
           D                        CA
           E                        CB
           F                        OA
           G                        QB
           H                        QA
           I                        NA
           J                        QC
           K                        PA
           L                        JA
