    New chain ID            Original chain ID

9cop-pdb-bundle1.pdb:
           A                         A
           B                         B
           E                         E
           F                         F
           I                         I
           J                         J
           K                         K
           L                         L
           M                         M
           N                         N
           P                         P
           x                         x
           y                         y
           z                         z
