    New chain ID            Original chain ID

7rl0-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           F                         F
           G                         G
           H                         H
           W                         W
           X                         X
           Y                         Y

7rl0-pdb-bundle2.pdb:
           Z                         Z
