    New chain ID            Original chain ID

6kmw-pdb-bundle1.pdb:
           A                        aA
           B                        aB
           C                        aC
           D                        aD
           E                        aE
           F                        aI
           G                        aL
           H                        aM
           I                        bA
           J                        bB
           K                        bC
           L                        bD
           M                        bE
           N                        bI
           O                        bL
           P                        bM
           Q                        cA
           R                        cB
           S                        cC
           T                        cD
           U                        cE
           V                        cI
           W                        cL
           X                        cM
