    New chain ID            Original chain ID

4v4u-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           S                         S
           T                         T
           U                         U
           V                         V
           W                         W
           F                         F
           G                         G
           H                         H
           I                         I
           J                         J
           K                         K
           L                         L
           M                         M
           N                         N
           O                         O
           P                         P

4v4u-pdb-bundle2.pdb:
           Q                         Q
