    New chain ID            Original chain ID

7wtn-pdb-bundle1.pdb:
           A                        C2
           B                        SB
           C                        SC
           D                        SE
           E                        SG
           F                        SH
           G                        SI
           H                        SJ
           I                        SL
           J                        SN
           K                        SO
           L                        SW
           M                        SX
           N                        SY
           O                        Sb
           P                        Se
           Q                        CA
           R                        CB
