    New chain ID            Original chain ID

6rxu-pdb-bundle1.pdb:
           A                        UA
           B                        UB
           C                        UC
           D                        UD
           E                        UF
           F                        UG
           G                        UJ
           H                        UK
           I                        UL
           J                        UM
           K                        UN
           L                        UO
           M                        UQ
           N                        UR
           O                        UU
           P                        UX
           Q                        UZ
           R                        CA
           S                        CB
           T                        CC
           U                        CD
           V                        CE
           W                        CF
           X                        CG
           Y                        CH
           Z                        CI
           a                        CJ
           b                        CK
           c                        CL

6rxu-pdb-bundle2.pdb:
           A                        CM
           B                        CN
           C                        CO
           D                        CP
           E                        CQ
           F                        CR
           G                        CS
           H                        CT
           I                        Ca
           J                        Cb
           K                        Cc
           L                        Cd
           M                        Ce
           N                        Cf
           O                        Cg
           P                        Ch
           Q                        Ci
           R                        Cj
           S                        Ck
           T                        Cm
           U                        Cn
           V                        Co
           W                        Cp
           X                        CU
           Y                        C1
           Z                        C2
           a                        CW
           b                        UT

6rxu-pdb-bundle3.pdb:
           A                        UH
           B                        UE
           C                        US
           D                        Cl
           E                        CX
           F                        CY
           G                        CZ
           H                        UI
           I                        UP
