I have a protonated GLU in the active site of an enzyme. I would like to use GLU_P1.params in my simulation by -extra_res_fa (the OE2 is protonated). I need to change the name of this protonated GLU in the PDB, but I am not sure what it should be. Because the NAME and IO_STRING are different and are not three letter code. Please see below and let me know what the name of this protonated GLU in the PDB file should be.