    New chain ID            Original chain ID

6n2y-pdb-bundle1.pdb:
           A                         A
           B                         B
           C                         C
           D                         D
           E                         E
           F                         F
           G                         G
           H                         H
           I                         I
           J                        b2
           K                        b1
           L                         a
           M                        c0
           N                        c1
           O                        c2
           P                        c3
           Q                        c4
           R                        c5
           S                        c6
           T                        c7
           U                        c8
           V                        c9
