    New chain ID            Original chain ID

9p4v-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           I                         I
           J                         J
           N                         N

9p4v-pdb-bundle2.pdb:
           O                         O
           T                         T
           U                         U
           1                         1
           Z                         Z
