    New chain ID            Original chain ID

6y60-pdb-bundle1.pdb:
           A                       AAA
           B                       BBB
           C                       CCC
           D                       DDD
           E                       EEE
           F                       FFF
           G                       GGG
           H                       HHH
           I                       III
           J                       JJJ
           K                         A
           L                         B
           M                         C
           N                         D
           O                         E
           P                         F
           Q                         G
