    New chain ID            Original chain ID

7rl5-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           M                         M
           P                         P
           R                         R
           L                         L
           O                         O
           Q                         Q

7rl5-pdb-bundle2.pdb:
           S                         S
