    New chain ID            Original chain ID

7kzp-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           E                         E
           F                         F
           G                         G
           H                         H
           L                         L
           M                         M
           O                         O
           P                         P

7kzp-pdb-bundle2.pdb:
           Q                         Q
           S                         S
           W                         W
