I am working with a protein that is a physiological dimer. On occasion I obtain a unit cell with one monomer in the asymmetric unit but most often I obtain an enantiomorphic space group with an expanded C axis that contains two molecules in the asymmetric unit. Anyway, that is all moot to some extent. I am wondering if for the case of my NCS dimer, is there a way using Phaser in Phenix to ensure that when both monomers are found, they are "close together" representative of the physiological dimer? When I search with individual monomers I often obtain a solution with two monomers but in different asymmetric units. Of course, I could easily do the transformation to form the physiological NCS dimer for later refinement but just wondering if I could avoid this from the get go with the appropriate Phaser keyword input (GUI if possible).

Thanks and Happy Holidays!

Joe