    New chain ID            Original chain ID

8ixl-pdb-bundle1.pdb:
           A                         Z
           B                         B
           C                         C
           D                         D
           E                         E
           F                         F
           G                         H
           H                         A
           I                         G
           J                         I
           K                         J
           L                         K
           M                         L
           N                         M
           O                         N
           P                         O
           Q                         P
           R                         Q
           S                         R
           T                         S
           U                         T
           V                         V
           W                         W
           X                         X
           Y                         Y
           Z                        AA
           a                        BA
           b                        CA
           c                        DA
           d                        EA
           e                        FA
           f                        GA
           g                        HA
           h                        IA
           i                        JA
