    New chain ID            Original chain ID

6rxz-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

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

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