    New chain ID            Original chain ID

8piu-pdb-bundle1.pdb:
           A                         B
           B                        AB
           C                         A
           D                        BB
           E                        CB
           F                        DB
           G                        EB
           H                        FB
           I                        GB
           J                        HB
           K                        IB
           L                         C
           M                         D
           N                         E
           O                         F
           P                         G
           Q                         H
           R                         I
           S                         J
           T                         K
           U                         L
           V                         M
           W                         N
           X                         O
           Y                         P
           Z                         Q
           a                         R
           b                        BA
           c                         S
           d                         T
           e                         V
           f                         W
           g                         X
           h                         Y
           i                         Z
           j                        AA
           k                        CA
           l                        DA
           m                        EA
           n                        FA
           o                        GA
           p                        HA
           q                        IA
           r                        JA
           s                        KA
           t                        LA
           u                        MA
           v                        NA
           w                        OA
           x                        PA
           y                        QA
           z                        RA
           0                        SA
           1                        TA
           2                        UA
           3                        VA

8piu-pdb-bundle2.pdb:
           A                        WA
           B                        XA
           C                        YA
           D                        ZA
