hello, everyone:
    I am a new user. I am analyzing the tetramer interfaces of SABP2 protein(pdb code: 1y7i). I download the SABP2 protein structure(pdb code: 1y7i) from pdb database, but the structure is dimer.could you tell me how to analyze  SABP2 tetramer interface and calculate interaction area and complexation energy.
 with best regards
                                                                 Jun Huang