    New chain ID            Original chain ID

6u48-pdb-bundle1.pdb:
           A                        CA
           B                        CB
           C                        CC
           D                        CD
           E                        CE
           F                        CF
           G                        CG
           H                        CH
           I                        CJ
           J                        CK
           K                        CL
           L                        CM
           M                        CN
           N                        CO
           O                        CP
           P                        CQ
           Q                        CR
           R                        CS
           S                        CT
           T                        CU
           U                        CV
           V                        CW
           W                        CX
           X                        CY
           Y                        CZ
           Z                        C0
           a                        C1
           b                        C2
           c                        C3
           d                        C4
           e                        C5
           f                         A
