    New chain ID            Original chain ID

7rd1-pdb-bundle1.pdb:
           0                         0
           U                         U
           1                         1
           V                         V
           2                         2
           W                         W
           3                         3
           X                         X
           4                         4
           Y                         Y
           8                         8
           Z                         Z
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           F                         F

7rd1-pdb-bundle2.pdb:
           G                         G
           H                         H
           I                         I
           J                         J
           K                         K
           L                         L
           M                         M
           N                         N
           O                         O
           P                         P
           Q                         Q

7rd1-pdb-bundle3.pdb:
           R                         R
           S                         S
           T                         T
