    New chain ID            Original chain ID

6dnc-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D

6dnc-pdb-bundle2.pdb:
           A                         E
           B                         F
           C                         G
           D                         H
           E                         I
           F                         J
           G                         K
           H                         L
           I                         M
           J                         N
           K                         O
           L                         P
           M                         Q
           N                         R
           O                         S
           P                         T
           Q                         U
           R                         V
           S                         W
           T                         X
           U                         Y
           V                         Z
           W                        AA
           X                        BA
           Y                        CA
           Z                        DA
           a                        EA
           b                        FA
           c                        GA
           d                        HA
           e                        IA
           f                        JA
           g                        KA
           h                        LA
           i                        MA
           j                        OA
           k                        PA
           l                        QA
           m                        RA
           n                        SA
           o                        TA
           p                        UA
           q                        VA
           r                        WA
           s                        XA
           t                        YA
           u                        ZA
           v                        AB
           w                        BB
           x                        CB
           y                        DB
           z                        EB
           0                        FB
           1                        GB
           2                        HB
