    New chain ID            Original chain ID

9gxe-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           F                         F
           G                        AA
           H                        AB
           I                        AC
           J                        BA
           K                        BB
           L                        BC
           M                        CA
           N                        CB
           O                        CC
