    New chain ID            Original chain ID

9rt2-pdb-bundle1.pdb:
           A                        N1
           B                        C1
           C                        N2
           D                        N3
           E                        C2
           F                        N4
           G                        N5
           H                        C3
           I                        N6
           J                        N7
           K                        C4
           L                        N8
