    New chain ID            Original chain ID

9r3d-pdb-bundle1.pdb:
           A                         5
           B                         6
           C                         B
           D                         C
           E                         I
           F                         K
           G                         Q
           H                         T
           I                         X
           J                         Z
           K                         q
           L                         r
           M                        P7
           N                         A
           O                         P
           P                         t
           Q                        S1
