    New chain ID            Original chain ID

9cz2-pdb-bundle1.pdb:
           A                        XA
           B                        XB
           C                        XC
           D                        XD
           E                        XE
           F                        XF
           G                        XG
           H                        XH
           I                        XI
           J                        XJ
           K                        XK
           L                        XL
           M                        XM
           N                        XN
           O                        XO
           P                        XP
           Q                        XQ
           R                        XR
           S                        XS
           T                        XT
           U                        XU
           V                        XX
           W                        XV

9cz2-pdb-bundle2.pdb:
           A                        XW
           B                         A
           C                         B
           D                         C
           E                         D
           F                         E
           G                         F
           H                         G
           I                         H
           J                         I
           K                         J
           L                         K
           M                         L
