    New chain ID            Original chain ID

9s72-pdb-bundle1.pdb:
           A                         A
           b                         b
           C                         C
           D                         D
           e                         e
           F                         F
           g                         g
           h                         h
           a                         a
           B                         B
           c                         c
           d                         d

9s72-pdb-bundle2.pdb:
           E                         E
           f                         f
           G                         G
           H                         H
